APPROACH TO CHILD WITH PURPURA

By Muhammad Jawad.

Questions What is the definition of purpuric rash?

What are the causes of purpura?

How to approach such a case?

Definition red, nonblanching maculopapular lesions

caused by intradermal capillary bleeding. classified as

o petechiae (pinpoint hemorrhages less than 2 mm in greatest diameter),

o purpura (2 mm to 1 cm) or o ecchymoses (more than 1 cm).

results from the extravasation of blood from the vasculature into the skin or mucous membranes.

Causes

Pupura

Platelet Vascular

Function Count Congenit

al Acquire

d

Thrombocytopenia may be caused by

increased platelet destruction Immune nonimmune

decreased platelet production Congenital Acquired

sequestration of platelets.

Immune Thrombocytopenia Idiopathic (immune) thrombocytopenic

purpura by far the most common etiology of

thrombocytopenia in childhood. caused by the development of IgG

autoantibodies to platelet membrane antigens as a result of an unbalanced response to an infectious agent or autoimmunity

sudden onset of bruises, purpura, mucosal hemorrhage and petechiae in a child who is otherwise in excellent health.

ITP antecedent viral infection is common. The peak incidence is between two and

four years of age. 80 to 90 percent of children recovering

within six to 12 months. Chronic idiopathic thrombocytopenic

purpura is more likely to present in teenage girls and children with underlying immune disorders. It has a more insidious onset

Immune Thrombocytopenia Drugs

penicillin, valproic acid (Depakene), quinidine, sulfonamides, cimetidine (Tagamet) and heparin.

Post-transfusion purpura acute onset of thrombocytopenia approximately

five to 14 days after a transfusion. Rarely

HIV, CMV, HSV 10% of SLE cases

Immune Thrombocytopenia Neonatal isoimmune (alloimmune)

thrombocytopenia

Neonatal autoimmune thrombocytopenia

Non-Immune Thrombocytopenia hemolytic-uremic syndrome

triad of microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury.

infection by verotoxin-producing Escherichia coli

thrombotic thrombocytopenic purpura occurs more often in adults, and neurologic

(rather than renal) symptoms are more prominent

Non-Immune Thrombocytopenia disseminated intravascular coagulopathy

overwhelming sepsis, incompatible blood transfusion, snake bite, giant hemangioma and malignancy.

Purpura fulminans acute, often lethal syndrome of DIC. may develop because of a severe bacterial

infection, notably meningococcal disease, or because of protein C or S deficiency

Decreased Platelet Production Congenital

Thrombocytopenia absent radii (TAR) syndrome inherited as an autosomal recessive trait

Fanconi anemia pancytopenia, hyperpigmentation and café au

lait spots, short stature, skeletal abnormalities Wiskott-Aldrich syndrome

should be considered in young males having thrombocytopenia with small platelets.

Decreased Platelet Production Acquired

Bone marrow suppression Drugs such as alkylating agents,

antimetabolites, anticonvulsants, chlorothiazide diuretics and estrogens

Infection as viral and bacterial infections, especially septicemia and Intrauterine infection with TORCH organisms

Bone marrow infiltration patients with leukemia, storage diseases,

neuroblastoma, and osteopetrosis

Sequestration of Platelets Splenomegaly or giant hemangioma can

result in thrombocytopenia because of platelet sequestration.

The association of thrombocytopenia and giant hemangioma is referred to as Kasabach-Merritt syndrome.

Platelet Dysfunction Glanzmann's thrombasthenia

autosomal recessive disorder caused by congenital deficiency in the platelet membrane glycoproteins IIb and IIIa.

Bernard-Soulier disease autosomal recessive disorder caused by a

congenital deficiency in platelet membrane glycoprotein Ib

Vascular Factors Congenital Causes

Hereditary hemorrhagic telangiectasia autosomal dominant disorder development of fragile telangiectasia of the

skin and mucous membranes Ehlers-Danlos syndrome

characterized by skin hyperelasticity, joint hypermobility and fragility of the skin and blood vessels

Vascular Factors Acquired Causes

Henoch-Schönlein purpura IgA-mediated systemic vasculitis of small

blood vessels nonthrombocytopenic purpura, abdominal

pain, arthritis and nephritis the most common form of vasculitis in

children history of a preceding URTI Characteristically palpable, gravity

dependant purpura

Vascular Factors Acquired Causes

Meningococcemia and rickettsial diseases may cause direct damage to blood vessels, with resultant purpura.

Child abuse

History Age of Onset     Birth   Intrauterine infection, maternal

idiopathic thrombocytopenic purpura, maternal systemic lupus erythematosus, maternal medication, TAR syndrome, congenital amegakaryocytic thrombocytopenia

2 to 4 years   Idiopathic thrombocytopenic purpura

4 to 7 years   Henoch-Schönlein purpura

History Onset/chronicity     Acute onset   ITP, HSP, medication,

mechanical cause Long duration   Abnormality of platelets,

coagulopathy

History Pattern of bleeding     Mucosal bleeding   Thrombocytopenia,

von Willebrand's disease Intramuscular and intra-articular

bleeding   Hemophilia

History Associated symptoms     Abdominal pain, blood in stools, joint pain  

HSP Lethargy, fever, bone pain  

Leukemia Intermittent fever, muscoskeletal symptoms  

SLE Lethargy, polyuria, polydipsia, failure to

thrive   Uremia Purpura, but otherwise healthy   ITP

History Past health     Antecedent viral infection, especially an

upper respiratory tract infection   ITP, HSP

Drug use Family history Maternal history Social history

Examination Characteristics of purpura     Location on lower extremeties   Henoch-

Schönlein purpura Location on palms and soles   Rickettsial

infection Palpable purpura   Vasculitis

Laboratory Evaluation A thorough history and a careful

physical examination are critical first steps in the evaluation of children with purpura.

RED FLAGS Fever, lethargy, weight loss, bone pain,joint pain,pallor, Lymphadenopathy hepatosplenomegaly

Summary Petechiae and purpura result from a wide variety

of underlying disorders and may occur at any age red, nonblanching maculopapular lesions caused

by intradermal capillary bleeding Classified into platelet or vascular causes Idiopathic thrombocytopenic purpura is the most

common cause of thrombocytopenia in children. Henoch-Schönlein purpura is the most common

form of vasculitis in children, and the purpuric rash is almost always palpable.