HSP affects mostly children and involves the skin and connective tissues, gastrointestinal tract, joints, and scrotum as well as the kidneys. HSP also occurs in adults, although less commonly than in children. Diagnosis is clinical and not based on laboratory evaluation. Routine lab test results are usually within reference ranges. A normal lipase makes acute pancreatitis very unlikely.
Eosinophilia sometimes is present.
Abdominal ultrasound may be better than barium enema to diagnose intussusception, since HSP-related intussusception more often is ileoileal instead of ileocolic as is typical in idiopathic intussusception. Doppler or radionuclide testicular scan shows normal or increased blood flow in HSP, in contrast to the decreased blood flow seen in testicular torsion. Consultation is recommended for patients with renal involvement prior to discharge from the ED and for all patients who appear acutely ill. Clinicians often use corticosteroids to treat abdominal pain, subcutaneous edema, and nephritis, but no prospective, placebo-controlled studies have demonstrated their effectiveness. Most patients recover quickly without treatment.