Approach to the patient with rash

Dr AJIT GADEKAR

High yield facts

• Primary lesions are uncomplicated abnormalities which represent initial pathologic change.

• Secondary changes reflect progression of disease eg excoriation , infection , keratinization.

• Physician must search for the primary lesion

High yield facts

• Look at the morphology and grouping to reach the diagnosis

• Clinician must know the pattern of emergency dermatologic conditions

• Clinician must communicate to the patient that there are times when it is difficult to narrow the final diagnosis to single entity

Aim

• To classify benign vs malignant • To know which need urgent care from those

which do not

History : series of questions

• What do the patient think is causing rash?

• Where did the lesions originate?

• When did the lesion first develop? & what has been the progression of rash

• Was there any prodrome to the lesions?

• What are the associated symptoms?

History : series of questions

• Does it itch , hurt etc?• What treatment was applied if any?• Is there h/o atopy in family?• What medication do they take regularly or

intermittently?• What kind of exposure do they have?• Family history of skin related disorder?

Physical • Diagnosis relies heavily on careful inspection of

the skin.• Examine in well-lit area where one can examine

the entire skin surface• Entire eruption should be visualized to evaluate

distribution and configuration• Most important objective is to characterize the

morphology of the primary lesion• Description of rash should include morphology,

color, configuration and distribution

Morphology : primary & secondary lesions

• Primary lesions are uncomplicated abnormalities which represent initial pathologic change

• Secondary changes reflect progression of disease such as excoriation , infection or keratinization

• Morphologic expression of dermatologic condition is basic entity on which all diagnosis are founded

Primary lesions • Macule : circumscribed flat discoloration < 1cm in diameter eg ash-leaf spots, flat nevi and freckle• Patch : circumscribed flat discoloration > 1cm in diameter eg vitiligo, tinea versicolor. Often have fine scale

(pityriasis alba) Papule : circumscribed superficial solid

elevated lesion < 1cm ,eg warts, elevated nevi insect bites molluscum contagiosum.

Primary lesions • Plaque : > 1cm elevated flat top superficial

lesion eg psoriasis and pityriasis rosea.• Vesicle : fluid filled lesion < 1cm in diameter eg herpes simplex and varicella• Bulla : fluid filled lesion > 1cm in diameter eg ssss and bullous impetigo• Pustule: vesicle with purulent exudates eg acne , folliculitis

Primary lesions

• Nodule : lesion < 1cm in diameter with depth eg secondary / tertiary syphilis• Tumor : > 1cm solid lesion with depth • Petechiae : pinpoint < 1cm flat red spots under

the skin surface• Purpura : > 1cm visible collection blood eg itp• Wheal : transient edematous papule or plaque

with pale center and pink margin, peripheral erythema eg hives and insect bites

Secondary lesions• Scales : dry and greasy masses of keratin

ranging from fine and delicate to coarse , implies pathologic process in epidermis

• Crust : dried exudates ( pus or blood)• Excoriation : linear abrasion caused by

scratching• Fissure : linear crack or cleavage on skin with

sharply defined margins

Secondary lesions

• Ulcer :depressed lesion with epidermal & dermal loss

• Scar : permanent lesion result from process of repair by replacing connective tissue

• Lichenification : area of increased epidermal thickness with accentuation of skin

Diagnostic features of lesion

• Distribution• Configuration• Color• Texture sandpaper texture in scarlet fever• Positive nikolskys sign epithelial shearing

caused by lateral pressure to unblistered skin

Distribution

Configuration

• General shape or the pattern in which the lesion are arranged

• Lesions may be grouped into a pattern eg grouped papule in molluscum contagiosum

• Form specific shape annular plaque of tinea corporis

• Herpes simplex typically present in grouped vesicles

An algorithmic approach

True emergencies in the pediatric dermatologic presentation

• Toxic epidermal necrolysis (TEN)• Stevens Johnson syndrome (SJS)• Staphylococcal scalded skin syndrome (SSSS)• Toxic shock syndrome (TSS)• Kawasaki disease (KD)• Anaphylaxis • Purpura fulminans

Toxic epidermal necrolysis (TEN)

• Definition : sudden onset : generalization in 24 – 48hrs : widespread blister formation : confluent erythema : skin tenderness : absence of target lesion : sever form of EM• Hypersensitivity that result in damage to basal

layer of epidermis

Toxic epidermal necrolysis

• Nikolskys sign positive• Fever , inflammation of eyelid , conjunctivae,

mouth precedes skin lesion• Complicated by dehydration shock electrolyte

imbalance septicemia

Stevens-johnson syndrome

• Erythema , edema of lips , buccal mucosa• Then devolopes bullae ulceration hemorrhagic

crusting• Skin lesions are bullae denuded skin .more

widespread than EM• Skin tenderness is minimal to absent• Pain from mucosal ulceration is painful• Systemic involvement present

SSSS

• Caused predominantly by phage group 2 staphylococci , strain 71 & 55

• Common in infant and young children's• Clinical features are mediated by

hematogenous spread in absence of specific antitoxin antibody to staphylococcal epidermolytic or exfoliative toxins A or B

• ↓ clearance of these toxin in young infant

SSSS

• Range from localized bullous impetigo to generalized cutaneous involvement with systemic illness

• Begins as cutaneous scarlentiform erythema• Desquamative phase begins 5 days after

cutaneous erythema• Sterile flaccid blisters devolopes diffusely• Intact bullae are consistently sterile unlike in

bullous impetigo

SSSS

SSSS

• Nikolskys sign positive .• Absence of inflammatory infiltrate is

charecteristics• semisynthetic penicillinase resistant penicillin

should be prescribed as staphylococci are resistant to penicillin

Erythema multiforme

• Characterized by abrupt , symmetric cutaneous eruption mostly on extensor upper extremities

• EM has numerous morphologic manifestation on the skin , varying from erythematous macules , papules , vesicles , bullae , or urticaria appearing plaques.

• Classic lesions doughnut-shaped, target like (iris or bulls eye) papule with erythematous outer border an inner pale ring dusky purple to necrotic center

Target or iris lesion with dusky zone on palm with EM due to HSV

Early fixed papule with central dusky zone on dorsum of hand in EM

EM etiology

• Infection with HSV is most common.• HSV labialis & HSV genitalis implicate in 60%

of episode of EM.• Trigger nearly all episodes of recurrent EM• HLA B35 / B62 / DR53 is associated with an

increased risk of HSV induced EM (recurrent).

Recurrent labial HSV

Meningococcemia

• Fever • Rash typically petechiae & purpura• Hypotension• Adrenal failure• Multiorgan failure • meningitis feature

Anaphylaxis

• Life threatening allergic reaction• Urticaria • angioedema • Wheezing • dyspnea • Hypotension• All these in few seconds to minutes of

exposure

Purpura fulminance

• Life threatening hemorhagic disease seen in setting of sepsis

• Skin lesions lead to perivascular hemorrhage and necrotic gangrene

• Presentation typically include fever hypotension DIC

Conclusion

• Approach to pediatric dermatology patient in the ED may appear daunting however with a systemic approach one can more readily and successfully arrive at a diagnosis and manage the patient effectively

Thank you…………………………………….