ALLERGY Question . 1. Which of the following are characteristic of allergens?

Proteins of molecular weight 70 kd

Lipopolysaccharides

Carbohydrates

Question . 2. Which of the following factors is characteristic of an atopic response?

Th1 release of cytokines promoting phagocytosis

Th1 release of cytokines promoting synthesis of opsonizing antibodies

Th1 and Th2 release of cytokines promoting synthesis of complement-fixing antibodies

Th2 release of cytokines promoting phagocytosis

Th2 release of cytokines promoting synthesis of IgE antibodies Explanation: Nonatopic subjects respond with the proliferation of T helper type 1 (Th1) cells, which secrete Th1 type cytokines (e.g., IFN- ) involved in the elicitation of allergen-specific IgG antibodies. Th1 cells are generally involved in the eradication of intracellular organisms such as mycobacteria, because of the ability of Th1 cytokines to activate phagocytes and promote the production of opsonizing and complement-fixing antibodies. However, genetically predisposed atopic individuals respond with a brisk expansion of T helper type 2 (Th2) cells that secrete cytokines favoring IgE synthesis. (See Chapter 130 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 3. Which of the following types of cells are distributed throughout connective tissues, often adjacent to blood vessels and below epithelial surfaces that are exposed to the external environment, and release a diverse array of mediators of allergic inflammation?

Eosinophils

Basophils

Mast cells Explanation: Mast cells contain or produce a diverse array of mediators of allergic inflammation. (See Chapter 130 in Nelson Textbook of Pediatrics, 17th ed.)

Th2 cells

Dendritic cells

Question . 4. Which of the following antigen-presenting cells are actively phagocytic and reside in peripheral sites such as the skin, intestinal lamina propria, and lungs?

Eosinophils

Basophils

Mast cells

Th2 cells

Dendritic cells Explanation: Antigen-presenting cells (APCs) are a heterogeneous group of cells that present antigens in the context of the major histocompatibility complex (MHC). Dendritic cells are actively phagocytic cells that reside in peripheral sites such as the skin, intestinal lamina propria, and lungs. (See Chapter 130 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 5. Which of the following statements best describes the relationship between allergic disorders and a possible genetic basis?

Allergic disorders are a response to only environmental factors

Allergic disorders are a response to only environmental factors and infectious agents

Asthma and allergic rhinitis are the only allergic disorders with a familial predisposition

Any familial predisposition is related to polymorphisms of a single gene located on chromosome 10 Explanation: Both environmental and genetic factors are important in allergic diseases. The clinical expression of these diseases is a complex interaction of many genetic loci and polymorphisms in each of these genes. (See Chapter 130 in Nelson Textbook of Pediatrics, 17th ed.)

Any familial predisposition is related to many genetic loci and also many polymorphisms

Question . 6. Which of the following factors may contribute to the worldwide rise in prevalence of allergic diseases, particularly in Westernized metropolitan areas?

Increasing genetic polymorphisms of CD14

Increased numbers of children in group daycare

Excessive use of antibiotics in first 2 yr of life Explanation: Widespread antibiotic use, particularly in young children, alters the microbial flora in the gastrointestinal tract and may produce an environment that is less effective in driving a Th1 response. (See Chapter 130 in Nelson Textbook of Pediatrics, 17th ed.)

Reduced exposure to pollutants in Westernized metropolitan areas since 1980

Reduced exposure to indoor allergens

Question . 7. All of the following may be signs of moderate to severe airway obstruction resulting from allergic response except:

Dennie lines (Dennie-Morgan folds) Explanation: Dennie lines (Dennie-Morgan folds) are prominent symmetric skinfolds that extend in an arc from the inner canthus beneath and parallel to the lower lid margin. Like allergic shiners and the allergic salute, they are signs of persistent rhinorrhea associated with allergic rhinitis. A "silent chest' in a patient with asthma (answer E) is a severe sign suggesting inspiratory and expiratory obstruction. Cyanosis is always present in such severe cases. (See Chapter 131 in Nelson Textbook of Pediatrics, 17th ed.)

Supraclavicular and intercostal retractions

Cyanosis

Pulsus paradoxus

Respiratory distress with minimal wheezing and a few crackles

Question . 8. A 7-yr-old boy with asthma has roughness over the extensor surfaces of the upper arms and thighs, which is caused by keratin plugs lodged in the openings of hair follicles. This physical finding is termed:

Keratosis pilaris Explanation: Xerosis, or dry skin, is the most common skin abnormality of allergic children. Keratosis pilaris, often found on the extensor surfaces of the upper arms and thighs, is characterized by roughness of the skin caused by discrete follicular papules. These are the result of hyperkeratosis with keratin plugs lodged in the openings of hair follicles, and re-form after removal. (See Chapter 131

in Nelson Textbook of Pediatrics, 17th ed.)

Fibroepitheliosis

Hidradenitis

Xerosis

Acrochordon

Question . 9. The radioallergosorbent test (RAST) determines:

Bronchial reactivity to subcutaneous serotonin

Bronchial reactivity after inhalation bronchial provocation test

The proportion of total allergic immunoglobulin

Antigen-specific serum IgE concentrations Explanation: The RAST (radioallergosorbent test) determines the serum IgE concentrations against specific antigens. The RAST correlates well with medical history and allergy skin testing but is somewhat less sensitive than skin testing. (See Chapter 131 in Nelson Textbook of Pediatrics, 17th ed.)

The overall allergic risk profile based on absolute eosinophil count, total IgE, and skin test results

Question . 10. All of the following statements regarding skin testing for allergic reactivity are true except:

Antihistamines given prior to testing may inhibit the reaction

Intradermal tests are more sensitive than puncture tests

Positive skin test results by intradermal testing correlate better than results by puncture tests with clinical symptoms Explanation: Positive skin test results obtained by the puncture technique correlate better than the more sensitive, less specific intradermal tests with measurements of specific IgE antibody and with the appearance of clinical symptoms on exposure to the allergen. (See Chapter 131

in Nelson Textbook of Pediatrics, 17th ed.)

The reaction peaks within approximately 20 min and usually resolves over 20-30 min

Larger reactions have greater clinical relevance

Question . 11. Which of the following is an advantage of skin testing over RAST to determine specific IgE?

Skin testing is not affected by administration of antihistamines

Skin testing has greater sensitivity than RAST Explanation: Because skin tests are more sensitive than RAST, they are more reliable than RAST in confirming risk of life-threatening anaphylactic conditions. All of the other responses are incorrect. (See Chapter 131 in Nelson Textbook of Pediatrics, 17th ed.)

Skin testing is semiquantitative

Skin testing is associated with less risk of allergic reaction

Skin testing is not confounded by dermographism

Question . 12. Which of the following physical findings would be least likely on examination of a child with moderate to severe asthma?

Tachypnea

Wheezing

Clubbing Explanation: Digital clubbing (hypertrophic pulmonary osteoarthropathy) is rarely observed in children with uncomplicated asthma and should prompt evaluation to exclude other potential diagnoses. (See Chapter 131 in Nelson Textbook of Pediatrics, 17th ed.)

Decreased air exchange over the right middle lobe

An increased anterior-posterior diameter of the chest

Question . 13. Recommendations to the parents of a child with dust mite allergy to help reduce dust mite exposure should include all of the following except:

Use a humidifier regularly Explanation: Household humidity should be kept at less than 50% to inhibit survival of mites. Use of vaporizers should be avoided. Dehumidifiers may be necessary in damp basements. The air conditioning should be set at the lowest level during the warmer months. Clothes and bedding should be washed in hot water (>130F) to kill dust mites. Carpeted flooring is not recommended. Carpet and upholstered furniture, if retained, should be vacuumed weekly using a vacuum with a HEPA filter. (See Chapter 132 in Nelson Textbook of Pediatrics, 17th ed.)

Place the mattress and pillow in allergen-proof encasements

Wash bed linens in hot water weekly

Remove the old carpet from the bedroom

Question . 14. All of the following statements regarding decreasing exposure to cat allergens are true except:

Removing the cat from the home is the most effective means of reducing exposure to cat allergen

Keeping the cat out of the child's bedroom and other rooms where the sensitized child spends large amounts of time reduces cat allergen exposure

Washing the cat regularly reduces cat allergen exposure

Using HEPA-filtered air cleaners does not reduce cat allergen exposure Explanation: Advice to remove a pet cat from the home or keep it outdoors is often ignored. In contrast to dust mite allergens, cat allergen is light and remains suspended in the air for long periods of time. Regular vacuuming with a HEPA-filtered and double-thickness-bag vacuum cleaner is encouraged. (See Chapter 132 in Nelson Textbook of Pediatrics, 17th ed.)

Removing carpet decreases cat allergen exposure

Question . 15. A 12-yr-old girl with moderate to severe asthma is sensitive to cat dander. Her family elects to remove the pet cat from the house, but to retain the present carpeting and upholstered furniture. What is the length of time required before the levels of cat allergen drop to levels found in homes without a cat?

Immediately

2 days

2 wk

2 mo

6 mo Explanation: Cat owners who remove the cat from the home without also removing carpeting and upholstered furniture, and thoroughly wiping down all walls and hard surfaces, should be informed not to expect immediate results. It may take 6 months to 1 year for the levels of cat allergen to drop to a level found in homes without a cat. (See Chapter 132 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 16. Which of the following statements regarding antihistamines is true?

Classification of antihistamines from type I to type VI is based on increasing antihistamine activity

Second-generation antihistamines are distinguished by greater effectiveness than first-generation antihistamines

Antihistamines should not be administered in combination with decongestants

Antihistamines are more effective in treating than preventing the action of histamine

The choice of antihistamines should be based on associated adverse effects and cost Explanation: There is little reason to choose one antihistamine over another except for avoidance of adverse effects, such as sedation, impairment of function, and cost. The chemical classification of antihistamines (type I to type VI) does not have functional significance. Second-generation antihistamines have fewer sedative adverse effects. (See Chapter 132 in Nelson Textbook of Pediatrics,

17th ed.)

Question . 17. Which of the following is an advantage of second-generation antihistamines over first-generation antihistamines?

Second-generation antihistamines are often less expensive

Second-generation antihistamines are more frequently available in oral preparations

Second-generation antihistamines have less of a sedative effect and produce less cognitive impairment

Explanation: One of the primary advantages of second-generation antihistamines is that they are nonsedating or much less so than first-generation antihistamines. (See Chapter 132 in Nelson Textbook of Pediatrics, 17th ed.)

Many more second-generation antihistamines are available as over-the-counter medications

Second-generation antihistamines are generally more effective than first-generation antihistamines

Question . 18. Which of the following statements regarding the use of cromolyn in the management of asthma is true?

Cromolyn prevents antibody-mediated mast cell degranulation and mediator release

Cromolyn prevents non-antibody-mediated mast cell degranulation

Cromolyn has no bronchodilator properties

The incidence of adverse effects is low

All of the above Explanation: Cromolyn prevents bronchoconstriction caused by immunologic as well as nonimmunologic stimuli (e.g., frigid air, exercise). It has no bronchodilator properties and is useful only if given prophylactically. (See Chapter 132 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 19. The type of adrenergic activity of drugs most desirable in treatment of asthma is:

1

2

1

2 Explanation: Agents with greater 2-selective activity provide effective bronchodilation with less cardiac stimulation (e.g., increase in heart rate) than may occur with agents with both 1 and 2 activities. (See Chapter 132

in Nelson Textbook of Pediatrics, 17th ed.)

3

Question . 20. A 4-yr-old boy experiences perennial clear rhinorrhea, nasal congestion, conjunctival injection, allergic shiners, nasal and ocular pruritus, and occasional fits of sneezing. An environmental history is significant for two cats in the home and flooding of the basement when it rains. He keeps twenty stuffed animals on his bed and sleeps with a feather pillow on an old mattress. He lives in a warm climate. Seasonal worsening of his symptoms has not been observed. He has perennial allergic rhinitis. Which of the following groups of allergens would be the most likely to contribute to his symptoms?

Dust mites, tree pollens, and weed pollens

Dust mites, animal danders, and molds Explanation: Perennial allergic rhinitis is most often associated with indoor allergens: house dust mites, animal danders, and molds. (See Chapter 133 in Nelson Textbook of Pediatrics, 17th ed.)

Tree, weed, and grass pollens

Tree pollen, grass pollen, and milk protein

Question . 21. A 7-yr-old girl presents with allergic nasal symptoms that are prominent from the middle of August through the first frost. Which of the following allergens is the most likely cause of her symptoms?

Milk protein

Tree pollen

Grass pollen

Weed pollen Explanation: In temperate climates, airborne pollen responsible for SAR appears in distinct phases: trees pollinate in the spring, grasses in the early summer, and weeds in the late summer. (See Chapter 133 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 22. A teenage boy presents in April with symptoms consistent with seasonal allergic rhinitis. On examination of his nose, which of the following findings suggest the need for further evaluation to exclude another diagnosis?

Nasal polyps Explanation: Nasal polyps and nasal septal deviation are structural disorders that can mimic allergic rhinitis. (See Chapter 133 in Nelson Textbook of Pediatrics, 17th ed.)

Pale-to-purple nasal mucosa

Thin, clear nasal secretions

A transverse nasal crease

Continuous open-mouth breathing

Question . 23. A 12-yr-old presents with sneezing, clear rhinorrhea, and nasal itching. Physical examination reveals boggy, pale nasal edema with a clear discharge. The most likely diagnosis is:

Foreign body

Vasomotor rhinitis

Neutrophilic rhinitis

Nasal mastocytosis

Allergic rhinitis Explanation: Allergic rhinitis is often seasonal and associated with allergic conjunctivitis. Eosinophils

predominate in the nasal secretions.Chapter 133

Question . 24. Two weeks later, the patient described in Question 23 complains of headache, poor nasal airflow requiring mouth breathing, fever, and a change in the nature of the nasal discharge to mucopurulent discharge. The most likely diagnosis is:

Sinusitis Explanation: Sinusitis is a possible complication of allergic rhinitis. A change in the nature of the nasal discharge, facial pain, and fever may all herald the onset of sinusitis. (See Chapter 133 in Nelson Textbook of Pediatrics, 17th ed.)

Foreign body

Rhinitis medicamentosa

Choanal stenosis

Ciliary dyskinesia

Question . 25. A 12-yr-old child presents with watery rhinorrhea, paroxysmal sneezing, and nasal obstruction. The serum IgE level is normal, and skin test results are negative. The physical examination is remarkable only for swollen turbinates and clear nasal secretions. A trial of antihistamine-decongestant therapy for 3 wk has not relieved symptoms. Which of the following is the recommended management?

Institute strict measures to avoid outdoor allergen exposure.

Begin seasonal use of oral sympathomimetic drugs.

Begin seasonal use of topical intranasal corticosteroids. Explanation: Topical intranasal corticosteroids (e.g., fluticasone, budesonide) should be used in children with allergic rhinitis that is resistant to antihistamine-decongestant therapy. A consultation with an allergist is recommended for patients with allergic rhinitis that does not respond to intranasal corticosteroids. (See Chapter 133 in Nelson Textbook of Pediatrics, 17th ed.)

Give a 10-day course of amoxicillin

Give a 10- to 14-day course of cefpodoxime

Question . 26. Which of the following is most useful in establishing the diagnosis of seasonal allergic rhinitis?

History of good clinical response to an intranasal corticosteroid preparation

History of exacerbation of symptoms in the spring Explanation: Seasonal allergic rhinitis follows a well-defined course of cyclical exacerbation, whereas perennial allergic rhinitis causes year-round symptoms.Chapter 133

Elevated serum IgE level

Positive result on skin testing for the house dust mite allergen

Nasal eosinophils

Question . 27. Common triggers of asthma in children include all of the following except:

Secondary tobacco smoke

Ozone

Cold air

Exercise

Gelatin Explanation: Asthma symptoms may be provoked by numerous events or exposures.Chapter 134

Question . 28. The parents of a 3-yr-old girl with a history of several previous coughing and wheezing exacerbations are wondering if their toddler is likely to develop persistent asthma. Which of the following is a strong risk factor for persistent asthma in toddlers with recurrent wheezing?

Eczema Explanation: Only a minority of young children who experience recurrent wheezing will go on to have persistent asthma in later childhood. Several risk factors have been identified. Chapter 134

Colic

Living on a farm

Female gender

Otitis media with effusion

Question . 29. A 4-yr-old boy with asthma has had mild wheezing only four times since you began treating him 6 mo ago with theophylline (Slo-bid Gyrocaps) twice each day. He previously experienced coughing and wheezing at least three times each week. (A peak serum theophylline concentration 5 mo ago was 16 g/mL). For the past 4 days, he has again experienced mild coughing and wheezing responsive to inhaled albuterol. Two days ago, an emergency department physician began treatment with erythromycin-sulfisoxazole (Pediazole) for otitis media. This morning the youngster began vomiting. The likely cause of the vomiting is:

Provocation by coughing (post-tussive emesis)

Sequelae of otitis media

Theophylline toxicity Explanation: The erythromycin (a macrolide antibiotic) component of Pediazole inhibits hepatic theophylline metabolism, thus potentially producing theophylline toxicity. (See Chapter 134 in Nelson Textbook of Pediatrics, 17th ed.)

Albuterol toxicity

Pediazole intolerance

Question . 30. A 10-yr-old child has intermittent symptoms of mild asthma. The most appropriate treatment option is:

Environmental control and patient education only?no medication is indicated

Oral theophylline

Cromolyn

Inhaled 2-agonist as needed for symptoms Explanation: For mild intermittent symptoms of asthma, recommended treatment is with a short-acting inhaled 2-agonist as needed for symptoms. The intensity of treatment depends on the severity of exacerbations. The need for short-acting inhaled 2-agonist use more than two times a week may indicate the need to initiate long-term-control therapy. (See Chapter 134 in Nelson Textbook of Pediatrics, 17th ed.)

Daily inhaled corticosteroid

Question . 31. The child described in Question 30 experiences worsening of symptoms, which are now persistent and of moderate severity. The most appropriate treatment option is:

Oral theophylline

Inhaled 2-agonist as needed for symptoms

Daily inhaled corticosteroid and oral theophylline

Daily inhaled corticosteroid and a long-acting inhaled 2-agonist

Explanation: For moderate persistent symptoms of asthma, recommended treatment is with a daily-inhaled corticosteroid and a long-acting inhaled 2-agonist. Alternatives to the inhaled 2-agonist are sustained-release theophylline and a leukotriene receptor antagonist. In addition, for moderate persistent symptoms of asthma, a short-acting 2-agonist is also used as needed for quick relief of symptoms.Chapter 134

Daily inhaled corticosteroid, a long-acting inhaled 2-agonist, and oral theophylline

Question . 32. A 12-yr-old asthmatic boy has developed an asthma exacerbation in the past few days. Asthma symptoms have continued to progress despite frequent albuterol use at home. He comes to the emergency department with chest tightness, dyspnea, and wheezing, and in moderate respiratory distress. In this setting, management should include all of the following except:

Close monitoring

Supplemental oxygen

Inhaled albuterol

Theophylline Explanation: Initial emergency department management of an asthma exacerbation includes close monitoring of clinical status, treatment with supplemental oxygen, inhaled

-agonist every 20 min for 1 hr, and if necessary, systemic glucocorticoids (2 mg/kg/day) given either orally or intravenously. Inhaled ipratropium may be added to the -agonist treatment if no significant response is seen with the first inhaled -agonist treatment. If a child responds poorly to intensive therapy with nebulized albuterol, ipratropium, and parenteral glucocorticoids, then adding intravenous theophylline could be considered.Chapter 134

Systemic glucocorticoids

Question . 33. A 7-yr-old girl has had intermittent asthma symptoms over the past 5 yr. Her asthma symptoms have been treated with inhaled albuterol as needed. She mostly has exercise-induced asthma symptoms, which happens on most school days except when she uses her albuterol inhaler before going to recess and physical education classes. In the past year, she has had two asthma exacerbations with viral upper respiratory tract infections, and she has used a total of 5 albuterol metered-dose inhalers. The most appropriate management for this asthmatic girl is:

Continue albuterol as needed and before physical exercise activities

Begin daily controller medication with an inhaled glucocorticoid, initially used more frequently to gain control, then a reduced amount in a few months to maintain control Explanation: Low-dose inhaled glucocorticoids, leukotriene pathway modifiers, and cromolyn/nedocromil are the recommended controllers for mild persistent asthmatics; sustained-release theophylline is an alternative. Chapter 134

Begin daily inhaled glucocorticoid in a low dose, increasing the dose monthly until good control is obtained

Administer daily oral glucocorticoid treatment for one week, with concurrent daily inhaled glucocorticoid

Begin use of a long-acting inhaled -agonist each morning

Question . 34. Components of the U.S. National Asthma Education & Prevention Program (NAEPP) guidelines include all of the following except:

Regular assessment and monitoring

Control of factors contributing to asthma severity

Asthma pharmacotherapy, especially the use of anti-inflammatory controller medications

Genetic profiling Explanation: The NAEPP guidelines were recently adapted for childhood asthma in a joint-effort publication of the American Academy of Allergy, Asthma & Immunology with the U.S. National Institutes of Health's National Heart, Lung and Blood Institute and the American Academy of Pediatrics entitled Pediatric Asthma: Promoting Best Practice.Chapter 134

Patient education

Question . 35. Features characteristically associated with atopic dermatitis include all of the following except:

Allergic rhinitis or asthma

Elevated serum IgE level

Peripheral blood eosinophilia

Lymphopenia Explanation: Most patients with atopic dermatitis have peripheral blood eosinophilia and elevated serum IgE level. Nearly 80% of patients with atopic dermatitis develop allergic rhinitis and/or asthma.

Question . 36. Major features of atopic dermatitis in children include all of the following except:

Pruritus

Facial and extensor eczema

Angioedema Explanation: Angioedema is similar to urticaria but has deeper tissue involvement. Urticaria and angioedema are not characteristic features of atopic dermatitis

Chronic or relapsing course

Personal or family history of atopic disease

Question . 37. A 2-yr-old is diagnosed with atopic dermatitis. Which of the following environmental modifications is recommended?

A bland diet, especially minimizing meats

Installation of wool carpeting instead of synthetic carpeting

Use of a liquid rather than powder laundry detergent, and adding a second rinse cycle Explanation: Using a liquid rather than a powder laundry detergent and adding a second rinse cycle will facilitate removal of the detergent. Soaps should have minimal defatting activity and a neutral pHChapter 135

Use of soaps that are especially effective in removing fatty substances

Bathing less often than daily

Question . 38. The most appropriate prognosis to convey to the parents of the 2-yr-old with atopic dermatitis described in Question 37 is:

The child will be asymptomatic with environmental modifications

Symptoms will gradually worsen during childhood and persist stably through adulthood

Symptoms will exhibit a remittent but progressively worsening course through adulthood

Symptoms will gradually decrease over the next several years with an approximately 50% chance of spontaneous improvement Explanation: Atopic dermatitis generally tends to be more severe and persistent in young children. With control of trigger factors and appropriate local treatment, reasonable but not complete resolution of symptoms is usually possible. Periods of remission appear more frequently as the child grows older. Spontaneous resolution of atopic dermatitis has been reported to occur after age 5 yr in 40-60% of patients affected during infancy, particularly if their disease is mild. Recent studies have reported that atopic dermatitis disappears in approximately 20% of children followed from infancy until adolescence, but it had become less severe in 65%. (See Chapter 135 in Nelson Textbook of Pediatrics, 17th ed.)

Symptoms will resolve completely at puberty

Question . 39. Which of the following is the major feature of atopic dermatitis?

Onset shortly before or during puberty

Pruritus Explanation: All patients with atopic dermatitis have pruritus. However, not all patients with atopic dermatitis have other allergic symptoms, elevated IgE levels, or S. aureus skin infections. (See Chapter 135 in Nelson Textbook of Pediatrics, 17th ed.)

C. Staphylococcus aureus cutaneous infections

Elevated serum IgE

Immediate skin test reactivity to allergens

Question . 40. A 5-yr-old boy with severe atopic dermatitis develops illness with dozens of vesicles primarily covering areas of skin previously affected by atopic dermatitis. The distribution crosses many dermatomes. Findings include fever and lymphadenopathy. The most likely diagnosis is:

Chickenpox

Zoster

Kaposi varicelliform eruption Explanation: Kaposi varicelliform eruption, or eczema herpeticum, results from herpes simplex virus infection of skin with altered immunity, usually from atopic dermatitis. Kaposi varicelliform eruption is clinically distinguished from zoster by its random distribution, which may involve many dermatomes. Additionally, lesions of eczema herpeticum are often isolated and are not grouped, as are the vesicles of zoster. Similar eruptions have been described in association with vaccinia virus (smallpox vaccination) and coxsackievirus infections. (See Chapter 135 in Nelson Textbook of Pediatrics, 17th ed.)

Eczema vaccinatum

Coxsackievirus infection

Question . 41. A 14-yr-old presents with acute-onset urticaria that has gradually worsened over the past 10 days. Detailed history reveals no clues to the possible etiology. Findings on physical examination are normal except for urticaria. Which of the following diagnostic options is recommended?

Systematic elimination diets to determine a possible ingestant cause

Allergy skin testing Explanation: No laboratory test confirms or excludes the diagnosis of urticaria. Allergy skin testing can be helpful in sorting out causes of acute urticaria, especially when supported by historical evidence. Drugs and foods are the most common causes of acute urticaria. A skin biopsy is indicated only if urticarial vasculitis is suspected. (See Chapter 136 in Nelson Textbook of Pediatrics, 17th ed.)

Serum IgE and RAST

Skin biopsy

None of the above

Question . 42. Which of the following treatment options is recommended for the patient described in Question 42?

A bland diet

Wearing cotton garments

Oral antihistamine Explanation: Antihistamines are usually effective for treatment of urticaria. Diphenhydramine and hydroxyzine are effective but also cause sedation. A nonsedating antihistamine (e.g., Loratadine) is often the preferred therapy for urticaria for school-aged children to minimize the effect on learning and school performance. (See Chapter 136 in Nelson Textbook of Pediatrics, 17th ed.)

Oral prednisone

Topical corticosteroid

Question . 43. Which of the following laboratory tests is most likely to give abnormal results in a patient with chronic urticaria?

Serum IgE level determination

Skin prick testing for egg sensitivity

C4 level assay

Assay for antibodies to thyroglobulin Explanation: There is an increased association of chronic urticaria with Hashimoto thyroiditis. Such patients generally have antibodies to thyroglobulin, or a microsomal-derived antigen (peroxidate) even if they are euthyroid. The incidence of abnormal thyroid function (either increased or decreased T4 and/or increased or decreased TSH) is approximately 20%. Patients with chronic urticaria usually have normal IgE levels. (See Chapter 136 in Nelson Textbook of Pediatrics, 17th ed.)

Heterophile antibody testing

Question . 44. A 12-yr-old girl with repeated episodes of streptococcal pharyngitis experiences another episode of sore throat. The rapid strep test result is positive, and oral amoxicillin is started, with the first dose given in the office. One hour later, she experiences a "funny feeling" and a tingling sensation around her mouth. Next she becomes apprehensive, has difficulty swallowing, and develops a hoarse voice. On arrival at the emergency department, she has giant urticaria and the following vital signs: pulse 130, respiratory rate 32/min, blood pressure 70/30 mm Hg, and temperature 37.2C. The most appropriate therapy is administration of:

Epinephrine Explanation: Intramuscular epinephrine is the treatment of choice. If the blood pressure does not respond, lactated Ringer's solution should be administered. Benadryl, cimetidine, and prednisone are second-line therapeutic agents to be administered after epinephrine and fluids. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Prednisone

Diphenhydramine

Albuterol

Lactated Ringer's solution

Question . 45. The most likely diagnosis for the patient described in Question 45 is:

Streptococcal toxic shock

Scarlet fever

Stevens-Johnson syndrome

Reye syndrome

Anaphylaxis Explanation: Anaphylaxis to penicillin usually occurs within 30-90 min of administration of this drug. Anaphylactic shock is often missed as a diagnosis unless a complete history is obtained and there is a high index of suspicion. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 46. The mother of an 8-yr-old boy with acute streptococcal tonsillitis calls to report that now, within 15 min after the first dose of oral penicillin V that you prescribed, he is complaining of itching and has developed hives. Which of the following should you recommend?

A dose of oral Benadryl, with instructions to call again if he has not improved within 30 min

Immediate return to your office or the nearest emergency department Explanation: The urticarial reaction described in the question may develop into anaphylaxis; the latter requires emergency treatment. In addition, the penicillin V should be stopped and a substitute nonpenicillin antibiotic chosen. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Careful monitoring at home, with instructions to return to your office or the nearest emergency department if he becomes short of breath or loses consciousness

Schedule a visit for a laboratory test to determine serum trypticase level

Substitution of erythromycin for penicillin

Question . 47. All of the following statements regarding anaphylaxis are true except:

Virtually any foreign substance can elicit an anaphylactic reaction

Most anaphylactic reactions are due to drugs, latex, foods, and Hymenoptera venom

Oral drugs carry a higher risk of anaphylaxis than that associated with injected drugs Explanation: Reactions to medications can be reduced and minimized by using oral medications in preference to injected forms. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Anaphylactic reactions to foods usually begin within minutes to 2 hr of exposure

Exercise alone can elicit an anaphylactoid reaction

Question . 48. Administration of which of the following drugs is the treatment of choice for anaphylaxis?

Diphenhydramine orally

Diphenhydramine by intravenous infusion

Aqueous epinephrine (1:1,000) by subcutaneous injection

Aqueous epinephrine (1:1,000) by intramuscular injection Explanation: The principal treatment of choice for anaphylaxis is aqueous epinephrine, 1:1,000, 0.01 mL/kg (maximum 0.3 mL for a child or 0.5 mL for an adult) by intramuscular injection, which can achieve more rapid effective concentrations than obtainable with subcutaneous injection. Intravenous epinephrine may be added as a continuous drip for persistent shock. Intramuscular or intravenous H1 and H2 antagonist antihistamines, oxygen, intravenous fluids, inhaled -agonists, and corticosteroids may also be required.

Aqueous epinephrine (1:1,000) by intravenous infusion

Question . 49. A 16-yr-old with history of anaphylaxis to Hymenoptera suffers a sting on an extremity. The first-aid kit that is available includes aqueous epinephrine 1:1,000 and other necessary medical supplies. All of the following measures for management of this sting are appropriate except:

Infiltration of one half of the epinephrine dose subcutaneously around the site of the sting

Repeat doses of aqueous epinephrine at 15-min intervals if necessary

Placement of a tourniquet above the site of the sting

Incision of and suction of venom from the site of the sting Explanation: With anaphylaxis due to injection of allergen extract or to a Hymenoptera sting on an extremity, one half of the dose of epinephrine may be diluted in 2 mL of normal saline and infiltrated subcutaneously at the site of the sting to slow absorption. Doses can be repeated at 15-min intervals if necessary. A tourniquet above the site can also slow systemic distribution. The tourniquet can be loosened after improvement or briefly at intervals of 3 min. Immediate transport to an appropriate medical facility should be arranged

Transport to an emergency department

Question . 50. The most common single cause of anaphylaxis outside of the hospital is:

Insect sting allergy

Drug allergy

Food allergy Explanation: Food allergy is the most common cause of anaphylaxis occurring outside of the hospital, accounting for about one half of the anaphylactic reactions reported in pediatric surveys. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Latex allergy

Food-associated exercise-induced anaphylaxis

Question . 51. A 12-yr-old child with a history of allergy to yellow jackets is stung and immediately begins experiencing tightness in the chest and wheezing. The drug of first choice for management of this child is:

Inhaled albuterol

Subcutaneous epinephrine

Intramuscular diphenhydramine

Intramuscular epinephrine Explanation: The principal treatment of choice of anaphylaxis is aqueous epinephrine, 1:1,000, 0.01 mL/kg (maximum 0.3 mL for a child or 0.5 mL for an adult) by intramuscular injection, which can achieve more rapid effective concentrations than obtainable with subcutaneous injection. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Oral corticosteroids

Question . 52. Which of the following would be the optimal long-term management of the child described in Question 51?

Daily oral non-sedating antihistamine

Daily low-dose oral corticosteroid

Daily inhaled corticosteroid

Inhaled corticosteroid immediately upon insect sting

Immunotherapy Explanation: Children experiencing systemic anaphylactic reactions to an insect sting should be evaluated and treated with immunotherapy, which is >90% protective. (See Chapter 137 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 53. A 2-yr-old child who has completed 8 days of a 10-day course of cefaclor presents with low-grade fever, malaise, irritability, lymphadenopathy, and a generalized erythematous rash that is mildly pruritic. The most likely diagnosis is:

Partially treated meningitis

Infectious mononucleosis

Kawasaki disease

Type I hypersensitivity reaction

Type III hypersensitivity reaction Explanation: Serum sickness is a classic example of a type III hypersensitivity reaction, or immune complex disease. The symptoms develop as antibodies appear against the antigen at a time when the antigen is still present. Immune complexes may stimulate complement and deposit in joints, the skin, and the renal glomeruli. (See Chapter 138 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 54. A 14-yr-old child received equine-derived antivenom for a snake bite 5 yr ago and now requires it again. Results of skin testing to the product are negative. Which of the following statements is true?

Premedication with corticosteroids is warranted to prevent serum sickness

Negative skin tests indicate that it is highly unlikely that he will develop serum sickness

He should not receive this product more than once

Serum sickness may begin within a few days of administration of the antivenom Explanation: Because he received the preparation previously, he may experience an accelerated form of serum sickness starting before the usual time course of 7-12 days following injection. Premedication with corticosteroids does not prevent serum sickness. Skin testing helps to identify the potential for immediate-type hypersensitivity (IgE antibody-mediated) to the serum components but does not predict serum sickness (a type III, immune complex-mediated hypersensitivity reaction). If there is no alternative treatment, then there is no contraindication to receive the product more than once. (See Chapter 138 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 55. Risk factors for adverse drug reactions include:

Topical administration (compared with parenteral administration)

Low dose (compared with high dose)

Frequent, intermittent dosing frequency (compared with prolonged, continuous dosing) Explanation: Risk factors for adverse drug reactions include previous exposure, previous reaction, age (20-49 yr), route of administration (parenteral), dose (high), and dosing schedule (intermittent), as well as genetic predisposition (e.g., in slow acetylators). Frequent, intermittent administration is more likely to elicit sensitization than prolonged, continual administration. (See Chapter 139 in Nelson Textbook of Pediatrics, 17th ed.)

No previous exposure (compared with previous administration)

All of the above

Question . 56. Which of the following statements concerning adverse drug reactions is true?

Adverse drug reactions are primarily IgE mediated

Drug-induced thrombocytopenia results from circulating immune complexes

Both parental and topical exposures to a drug increase the risk for an adverse reaction Explanation: Parenteral administration poses greater risk than topical administration, but both contribute to risk for an adverse reaction. Adverse drug reactions are immune complex reactions (Gell and Coombs type III)

Approximately 80% of patients with a history of penicillin allergy will have evidence of penicillin-specific IgE antibodies on testing

Epidermal detachment of >30% suggests Stevens-Johnson syndrome

Question . 57. A 7-yr-old boy presents with fever and otalgia. On examination, he has a bulging right tympanic membrane. As you hand his mother a prescription for amoxicillin, she informs you that when the child was 4 yr old, he broke out in an itchy rash during treatment with amoxicillin. The most appropriate approach to management of this patient would be:

Reassure the mother that since more than 2 yr have passed, it is highly unlikely that the child is still allergic and he can now take the amoxicillin safely

Explain to the mother that most adverse drug reactions to amoxicillin are not IgE mediated and that amoxicillin can be safely given.

Prescribe a cephalosporin and explain to the mother that there is no cross-reaction between penicillins and cephalosporins

Prescribe a macrolide antibiotic and explain to the mother that there is no cross-reaction between penicillins and macrolides Explanation: Risk factors for adverse drug reactions include previous exposure and previous reaction. A macrolide is recommended for otitis media in penicillin-allergic patients

Give the child a prescription for amoxicillin, and instruct the mother to pre-treat him with diphenhydramine (which is

available without a prescription)

Question . 58. The parents of a 6-yr-old girl relate a history of urticarial reaction and vomiting following administration of amoxicillin in the past. Skin testing to major and minor determinants of penicillin is positive. Which of the following statements regarding administration of a cephalosporin constitutes appropriate advice for the parents?

The child can receive a cephalosporin with no greater risk of anaphylaxis than in the general population

There is a 2% risk of anaphylaxis to a cephalosporin Explanation: Although the risk of allergic reactions to cephalosporins in patients with positive skin tests to penicillin appears to be low (less than 2%), anaphylactic reactions after administration of a cephalosporin have occurred in patients with a positive history of penicillin anaphylaxis. If a patient has a history of penicillin allergy and requires a cephalosporin, skin testing to major and minor determinants of penicillin should preferably be done to determine if the patient has penicillin-specific IgE antibodies. If results of skin tests are negative, the patient can receive a cephalosporin with no greater risk than in the general population. If skin tests are positive to penicillin, recommendations may include administration of an alternative antibiotic, cautious graded challenge with appropriate monitoring, in view of the 2% risk of an anaphylactic reaction, and desensitization to the required cephalosporin. (See Chapter 139 in Nelson Textbook of Pediatrics, 17th ed.)

There is a 9% risk of anaphylaxis to a first-generation cephalosporin but an almost 0% risk of anaphylaxis to a fourth generation cephalosporin

There is a 9% risk of anaphylaxis to a cephalosporin

There is a 50% risk of anaphylaxis to a cephalosporin

Question . 59. A 14-yr-old girl, who has a long-standing seizure disorder for which she takes phenytoin, develops fever and a urinary tract infection and is prescribed trimethoprim-sulfamethoxazole. After 9 days of antibiotic treatment she has recurrence of fever and develops confluent purpuric macules on her face and trunk with erosive mucosal lesions of her mouth and conjunctivae. A skin biopsy reveals 8% epidermal detachment. Which of the following best describes this disorder?

Toxic shock syndrome

Anticonvulsant hypersensitivity syndrome

Allergy to sulfamethoxazole

Stevens-Johnson syndrome Explanation: Stevens-Johnson syndrome is a blistering mucocutaneous disorder induced by drugs, classically sulfonamides. Epidermal detachment of less than 10% suggests Stevens-Johnson syndrome. (See Chapter 139 in Nelson Textbook of Pediatrics, 17th ed.)

Toxic epidermal necrolysis

Question . 60. All of the following may be manifestations of insect allergy except:

Rhinitis and conjunctivitis

Asthma

Wheal and flare

Anaphylaxis

Uveitis Explanation: Clinical findings in allergy caused by insects are similar to those occurring with usual inhalant allergens (e.g., rhinitis, conjunctivitis, asthma). Biting insects may cause local reactions that do not involve IgE. Venom from stinging insects causes IgE-mediated sensitivity that may lead to urticaria and anaphylaxis. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 61. All of the following statements concerning allergic reactions to stinging insects are true except:

The majority are due to Hymenoptera

There is substantial cross-reactivity among vespid venoms

Systemic reactions can occur after the first sting

Most reactions are IgE mediated

Negative results on skin testing and RAST reliably exclude the likelihood of anaphylaxis Explanation: There are patients with convincing histories of sting anaphylaxis with negative skin test results and RAST results. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 62. Immunotherapy provides symptomatic improvement in all of the following except:

Ragweed allergy

Local reaction to bee sting Explanation: Local reactions to Hymenoptera venom in children are not managed by immunotherapy. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

Tree pollen allergy

House dust mite allergy

Anaphylaxis to a wasp sting

Question . 63. An 8-yr-old boy experienced immediate urticaria surrounding a large local reaction to a honeybee sting 2 mo ago. He had no other symptoms. Skin testing with honeybee venom has been strongly positive at a weak concentration. Appropriate recommendations include all of the following except:

Hymenoptera venom immunotherapy Explanation: Immunotherapy is indicated only for systemic reactions. Individuals with local reactions are not at increased risk for severe systemic reactions on a subsequent sting and are not candidates for Hymenoptera venom immunotherapy. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

An epinephrine auto-injector (EpiPen) for administration after a subsequent sting

Wearing shoes when outdoors

A Medic-Alert bracelet

Wearing long pants

Question . 64. A 10-yr-old girl was stung on her left cheek by a yellow jacket. She is experiencing pain. By 4 hr following the sting the left side of her face is so swollen that her left eye is virtually closed. There are no other complaints. The best course of action would be:

Apply cold compresses, and consider antihistamines and pain medication Explanation: The child has experienced a large local reaction to the sting. Supportive care directed at the reaction is appropriate. Individuals who have experienced only large local reactions, or children younger than 17 yr who have experienced systemic reactions confined to the skin (generalized urticaria), are not at significantly increased risk for a severe systemic reaction upon subsequent stings, so testing for allergy and providing emergency medications are not warranted. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

Perform or refer her for skin testing to Hymenoptera venom

Prescribe self-injectable epinephrine and provide instructions to school/camp

All of the above

Question . 65. A 7-yr-old boy was stung by an unidentified insect and within minutes developed generalized urticaria, a repetitive cough, difficulty breathing, and extreme dizziness. He was treated in the emergency department with antihistamines, epinephrine, and corticosteroids. Which of the following statements is accurate?

If skin tests to Hymenoptera venom are performed 1 wk later and results are negative, he is not a candidate for venom immunotherapy

Testing and venom immunotherapy cannot be undertaken until the insect is identified

Venom immunotherapy could reduce the risk for a severe anaphylaxis on a subsequent sting from more than 50% to less than 3% Explanation: Venom immunotherapy is highly effective in reducing the risk of anaphylaxis. While venom immunotherapy carries some risks for local and systemic adverse effects, the benefits outweigh the risks for those at high risk for anaphylaxis from a subsequent sting. Those at high risk include any individual with positive results on skin tests/RAST who experienced a systemic reaction to a sting with symptoms beyond generalized skin rashes (e.g., respiratory, cardiovascular reactions) or those 17 yr of age and older with systemic reactions confined to the skin (generalized urticaria). Test results may be negative during a refractory period in the weeks following the reaction, so they should be repeated, along with RAST, after 4-6 wk if they are negative initially. It is not necessary to know exactly which insect caused the sting before proceeding with testing and treatment. Although venom immunotherapy may not be indicated for patients without identifiable IgE to the venom, in cases of anaphylaxis proximate to a sting, patients should be equipped with self-administered epinephrine because the risk for a subsequent anaphylactic reaction is increased. (See Chapter 140 in Nelson Textbook of Pediatrics, 17th ed.)

If results of venom skin tests are negative, he does not need to have self-administered epinephrine readily available

Question . 66. A 15-yr-old with a history of seasonal hay fever now also has itchy eyes, profuse tearing, and reddened and edematous conjunctivae. A treatment option effective for the ocular symptoms would be:

Topical antihistamines

Topical decongestants

Topical mast cell stabilizers

Topical nonsteroidal anti-inflammatory drugs

All of the above?each is an effective secondary treatment regimen for ocular allergies Explanation: Allergic conjunctivitis in the patient with hay fever generally responds well to treatment regimens including topical application of antihistamines, topical decongestants, topical mast cell stabilizers, and topical nonsteroidal anti-inflammatory drugs. Children often complain of stinging or burning with use of topical ophthalmic preparations and usually prefer oral antihistamines for allergic conjunctivitis. (See Chapter 141

in Nelson Textbook of Pediatrics, 17th ed.)

Question . 67. The patient described in Question 66 continues to have symptoms. The most appropriate next step in management would be:

Combination therapy such as with an antihistamine and a vasoconstrictive agent

Immunotherapy

Topical corticosteroids

Oral corticosteroids

All of the above?each is an effective tertiary treatment regimen for ocular allergies Explanation: Tertiary treatment of ocular allergy includes topical, or rarely oral, corticosteroids. Local administration of topical corticosteroids may be associated with increased intraocular pressure, viral infections, and cataract formation. Allergen immunotherapy can be very effective in seasonal and perennial allergic conjunctivitis, especially when associated with rhinitis. It can decrease the need for oral or topical medications to control allergy symptoms. (See Chapter 141 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 68. All of the following statements concerning allergic reactions to foods are true except:

Skin tests are of little diagnostic value for cell-mediated gastrointestinal hypersensitivity

Cow's milk sensitivity is the most common cause of protein-induced enteropathy

Gastrointestinal anaphylaxis is mediated by IgA Explanation: Gastrointestinal anaphylaxis generally presents as acute abdominal pain and vomiting that accompanies other IgE-mediated allergic symptoms. (See Chapter 142 in Nelson Textbook of Pediatrics, 17th ed.)

The majority of children with positive results on prick skin tests to a food will not react when the food is ingested

Elimination diets are the only means to establish the diagnosis of food allergies

Question . 69. Which of the following is an uncommon clinical manifestation of food allergies?

Acute urticaria

Angioedema

Wheezing

Diarrhea

Chronic fatigue Explanation: Chronic fatigue is not recognized to be caused by food allergies. Acute urticaria and angioedema (but not chronic urticaria and angioedema), acute rhinoconjunctivitis, bronchospasm (wheezing), vomiting, and protracted diarrhea are all manifestations of food allergies. (See Box 142-1 and Chapter 142 in Nelson Textbook of Pediatrics, 17th ed.)

Question . 70. All of the following foods are characteristically associated with allergy except:

Peanuts

Tree nuts

Legumes Explanation: Peanuts, tree nuts, eggs, and seafood all are characteristically associated with food allergies. (See Chapter 142 in Nelson Textbook of Pediatrics, 17th ed.)

Eggs

Seafood

Question . 71. Because of a strong family history on both sides, the parents of a newborn baby ask for guidance about preventing their child from developing an allergy to peanuts. Which of the following approaches is recommended?

Begin and extend breast-feeding until age 2 yr, with exclusion of peanuts from the mother's diet while breast-feeding

Begin and extend breast-feeding until age 2 yr, with the mother ingesting gradually increasing amounts of creamy peanut butter from 18-24 mo of age

Begin and continue breast-feeding as routinely recommended, with the mother regularly ingesting small amounts of peanuts but not introducing peanuts in the child's diet until age 1 yr

Begin and continue breast-feeding as routinely recommended, excluding peanuts from the mother's diet while breast-feeding and from the child's diet until age 3 yr Explanation: There is no consensus on whether food allergies can be prevented. However, several authorities recommend delaying introduction of major food allergens to infants from atopic families. Recommendations include promotion of breast-feeding with maternal exclusion of peanut and nut products from the mother's diet and delay in introducing major allergenic foods: cow's milk until 1 yr of age; egg until 18-24 mo of age, and peanuts, tree nuts, and seafood until 3 yr of age. (See Chapter 142 in Nelson Textbook of Pediatrics, 17th ed.)

Use only creamy peanut butter and not chunky peanut butter or whole peanuts in the child's diet (after 1 yr of age)

Question . 72. A 6-mo-old infant develops protracted projectile vomiting, and lethargy about 2 hr after ingesting a milk formula. The most likely diagnosis is:

Generalized anaphylaxis

Milk-induced enterocolitis syndrome Explanation: Food protein-induced enterocolitis syndrome typically manifests in the first several months of life with irritability, protracted vomiting and diarrhea, not infrequently resulting in dehydration. Vomiting generally occurs 1-3 hr following feeding, and continued exposure may result in bloody diarrhea, anemia, abdominal distention, and failure to thrive. Symptoms are most commonly provoked by cow's milk- or soy protein-based formulas but occasionally result from food proteins passed in maternal breast milk. (See Chapter 142

in Nelson Textbook of Pediatrics, 17th ed.)

Gastrointestinal anaphylaxis

Allergic eosinophilic esophagitis

Allergic eosinophilic gastroenteritis

Question . 73. Which of the following is the most definitive test for diagnosing a food protein-induced enterocolitis?

Positive clinical history

Positive food challenge Explanation: Unfortunately there are no laboratory studies that help identify foods responsible for cell-mediated reactions. Consequently, elimination diets followed by food challenges are the only way to establish the diagnosis. (See Chapter 142 in Nelson Textbook of Pediatrics, 17th ed.)

Positive result on skin prick test

Positive RAST result

Quantitative IgE level