Henoch-Schonlein Purpura (IgA Vasculitis)
5 year old presents with acute onset diffuse/colicky abdominal pain, arthralgias/arthritis, purpura. Symptoms preceded by sore throat. Hypertension and palpable, non-blanching purpura primarily located on lower extremities.
Labs
CBC may show thrombocytopenia
Obtain initial CMP to evaluate creatinine, serum albumin
Evaluate early morning CMP for creatinine > 30 µmol/L
Obtain PT/PTT/INR
Evaluate urinalysis for proteinuria, hematuria
Consider skin biopsy
Severe abdominal pain: Consider ultrasound to rule out intussusception
Treatment
Continue supportive therapy
Arthritic pain: Acetaminophen per pediatric dosing
Positive strep test and age > 3 years and GFR > 30: Amoxicillin 50 mg/kg qd x 10 days (maximum daily dose 1,000 mg/day)
Renal involvement as evidenced by elevated creatinine, proteinuria, and/or hematuria
Prednisone 1 mg/kg/day x 2 weeks followed by 2 week taper
HTN: Amlodipine 0.1 mg/kg/day (maximum daily dose 5 mg/day)
Consult nephrology
Monitor BP, creatinine, and urinalysis monthly for six months
Refractory abdominal/arthritic pain and/or scrotal swelling: Consider prednisone (see dosing above)
Counseling
Parents informed that 95% of cases resolve spontaneously within 8 weeks
Avoid ibuprofen due to abdominal pain and concern for renal involvement
Relapses can occur for up to 10 years following illness
Notes
Epidemiology
Most common systemic vasculitis of childhood
Typically occurs between age 3-15 years with peak prevalence at age 4-6 years
Only 10% of cases occur in adults
Sometimes associated with preceding streptococcal pharyngitis
Pediatric Rheumatology European Society Criteria
Mandatory: Purpura or petechiae with lower limb predominance
At least one of the following:
Arthritis or arthralgia
Acute onset diffuse abdominal pain
Renal involvement: Proteinuria or hematuria
Histopathology: Leukoclastic vasculitis or proliferative glomerulonephritis with IGA deposits
Treatment
Calcium channel blockers (e.g. amlodipine) are indicated for hypertension associated with renal involvement
Corticosteroids
Prophylactic treatment does not prevent renal disease (SOR A)
Early treatment may reduce joint and abdominal pain