Henoch-Schonlein is a type of hypersensitivity vasculitis and inflammatory response within the blood vessel. It is caused by an abnormal response of the immune system. The exact cause for this disorder is unknown.

The syndrome is usually seen in children, but people of any age may be affected. It is more common in boys than in girls. Many people with Henoch-Schonlein purpura had an upper respiratory illness in the previous weeks.

• purple spots on the skin (purpura), usually over the buttocks, lower legs, and elbows
• hives or angioedema
• joint pains
• abdominal pain
• nausea
• vomiting
• diarrhea
• stools, bloody
• menstruation, painful

• A physical examination reveals skin lesions and joint tenderness.
• A urinalysis shows microscopic blood in the urine.
• A skin biopsy shows vasculitis.

• recurrence of symptoms
• renal impairment (may occur in rare cases)

• Call for an appointment with your health care provider if symptoms of Henoch-Scholnlein purpura develop, particularly if they last for more than a few days.
• Call your health care provider if low urine output develops after an episode of Henoch-Schonlein purpura.