Henoch-Schönlein purpura (HSP)

• mnemonic: JARS - joints, abdominal pain, renal, skin
• Triad: CUTANEOUS, GI, RENAL
• Most common cause of purpura besides low platelets
• IgA Mediated small vessel vasculitis; systemic vasculitis of small vessels that affects the skin, gastrointestinal tract, joints, and kidneys

History

• Often follows viral illness

Who gets it

• Typically 2-8 y/o

Presentation

• Symptoms can occur acutely, or continue to appear over months and even a year
• Cutaneous: EDEMA: scrotal, extremity
  • RASH
    • may begin as erythematous macules or papules, but palpable purpura develops within several days.
    • Lesions are concentrated in dependent areas; thus, in an ambulatory patient, the buttocks and lower extremities are most affected.
    • Usually lower extremities
    • Involves head and arms oftentimes, but classically spares the trunk
    • Can last days to months
    • Although lesions may mimic those of meningococcemia, children who have HSP do not appear systemically ill, are afebrile or have only a low-grade fever, often have associated abdominal or joint pain, and do not have thrombocytopenia.
• ARTHRITIS/ ARTHRALGIA: Usually lower extremities –due to vasculitis, Non-erosive/ transient
• GI: 50% of those with GI involvement have Heme(+) stools, diarrhea, or hematemesis; Abdominal pain can be due to enlarged lymph nodes, segmental edema, etc; High suspicion for intussusception (ileo-ileal) – establish diagnosis with U/S
• RENAL
  • see Henoch-Schonlein Purpura Nephritis
  • 25-50% have signs of GN
  • This is the major cause of long term morbidity
  • Periodic urine dip checks after the acute phase has resolved - for about 6months to 1 year (at least 6 months even if the patient never had hematuria)
• DDX: Familial Mediterranean fever can present with a similar constellation of symptoms:
  • fever
  • lower extremity rash
  • serositis
    • acute severe peritonitis, often mimicking a surgical abdomen
    • pleuritis
    • monoarthritis

Labs

• Non-specific, and usually normal
• Mild elevation in WBC, Plts, ESR, or mild anemia from GI loss, normal C3/C4
• Can have elevated IgA/ IgM
• UA: hematuria, proteinuria, and occasional red cell casts
• To round out the differential, consider:
  • Amylase, lipase
  • Antistreptolysin-O (ASO) titer
  • Monospot
  • Antinuclear antibody (ANA)
  • ANCA
  • Rheumatoid factor (RF)
  • C3/C4 levels
  • Prothrombin time (PT)
  • Activated partial thromboplastin time (aPTT)
  • Blood cultures

Imaging is clinically indicated

• CT scanning may aid in the exclusion of other causes of abdominal pain.
• A barium enema or endoscopy might be needed for evaluation of epigastric pain, hematemesis, and melena.
• Ultrasonography may be helpful for intussusception and to exclude appendicitis.
• A chest radiograph should be obtained following hemoptysis, and a head CT is necessary if neurological symptoms persist. Imaging of the scrotum via ultrasonography or a technetium radionuclide scan may be necessary if scrotal edema is a presenting feature.

Treatment

• Observation is standard
• Patients with HSP have the potential for severe complications, which may present precipitously (eg, acute abdomen, acute scrotum, renal failure). All patients with the diagnosis of HSP should be admitted to the hospital for observation and monitoring.
• If the patient has renal involvement, consultation with a nephrologist should be obtained for assistance in determining whether dialysis is indicated. Because 1 in 20 patients with HSP have renal failure early, consultation is desirable.
• Rash/ arthritis –observe and symptomatic care with NSAIDS
• Edema –steroids
• GI –steroids if there is significant pain or involvement (no concensus–some studies suggest they get better regardless in 72hrs. Some suggest steroids only helps if given in first 72 hours))
• Renal –treat as per standard for GN (additional treatment with steroids has no concensus)
• General rule: treat with steroids if have “poor prognostic signs; If used, prednisone (1-2 mg/kg/d for 7 d) is recommended. Antihypertensives may be indicated with renal involvement.

Prognosis

• Generally excellent
• Fifty percent of patients have at least 1 recurrence. Younger patients (<3 y) usually have a better prognosis.
• recurrence within the first 6 weeks in up to 1/3
• Prognosis is best for patients with minimal or no renal involvement at the outset of the illness.

Complications

• GI complications include intussusception, bowel infarction, bowel perforation, hydrops of the gallbladder, pancreatitis, and GI bleeding.
• Overall, 5% of patients develop end-stage renal disease.
• HSP can involve nearly any organ system.
• Other potential complications include the following:
• Coronary artery vasculitis resulting in myocardial infarction (MI)
• Headache
• Irritability
• Fever
• Pulmonary hemorrhage
• CNS bleeding
• Scrotal edema
• Pain

Emedicine.com (updated July 26, 2002) and other sources