HENOCH-SCHÖNLEINPURPURA

Is a vasculitis of unknown etiology

characterized by inflammation of small blood

vessels with leukocytic infiltration associated

with IgA deposition.

EPIDEMIOLOGY• Most common systemic vasculitis of childhood

and cause of nonthrombocytopenic purpura, with an incidence of 13 per 100,000 children.

• It occurs primarily in children 3 to 15 years of age, although it has been described in adults.

• Is slightly more common in boys than girls and occurs more frequently in the winter than in the summer months.

CLINICAL MANIFESTATIONS

Characterized by rash, arthritis, gastrointestinal and renal

vasculitis. The hallmark is palpable purpura, caused by

small vessel inflammation in the skin leading to

extravasation of blood into the surrounding tissues.

• The rash is classically found in dependent areas: below the waist, on the buttocks, and lower extremities.

• The rash can begin as small macules or urticarial lesions but rapidly progresses to purpura with areas of ecchymosis.

• The rash also can be accompanied by edema, particularly of the calves and dorsum of the feet, scalp, and scrotum or labia.

• Arthritis occurs in 80% of patients and is most common in the lower extremities, particularly the ankles and knees.

• Joint swelling can be confused with peripheral edema seen with the rash.

• Gastrointestinal involvement occurs in about one half of affected children and most typically presents as mild to moderate crampy abdominal pain.

• Abdominal distention, bloody diarrhea, intussusception or abdominal perforation.

• Gastrointestinal involvement is typically seen during the acute phase of the illness. It may precede the onset of rash.

• One third of children develop renal involvement, which can be acute or chronic. Although renal involvement is mild in most cases, acute glomerulonephritis manifested by hematuria, hypertension, or acute renal failure can occur.

• Most cases of glomerulonephritis occur within the first few months of presentation, but rarely patients develop late renal disease.

LABORATORY AND IMAGING STUDIES

• VSG, PCR, and WBC are elevated.

• Platelet count is normal or even high (autoimmune thrombocytopenia, LES, or leukemia).

• Hematuria, BUN and creatinine.

• Testing the stool for blood (gut ischemia).

DIAGNOSIS

DIFFERENTIAL DIAGNOSIS

The differential diagnosis includes other systemic vasculitides and diseases associated with thrombocytopenic purpura, such as idiopathic thrombocytopenic purpura and leukemia.

TREATMENT• A short-term course of NSAID can be administered for the

acute arthritis.

• Systemic corticosteroids usually are reserved for children with gastrointestinal disease and provide significant relief of abdominal pain.

• Prednisone: 1 mg/kg/day for 1 to 2 weeks.

• Acute nephritis typically is treated with corticosteroids but may require more aggressive immunosuppressive therapy.