Diagnosis

Your doctor will be able to diagnose the condition as Henoch-Schonlein purpura if the classic rash, joint pain and digestive tract symptoms are present. If one of these signs and symptoms is missing, your doctor may suggest one or more of the following tests.

Lab tests

No single laboratory test can confirm Henoch-Schonlein purpura, but certain tests can help rule out other diseases and make a diagnosis of Henoch-Schonlein seem likely. They may include:

• Blood tests. Your blood may be tested if your diagnosis isn't clear based on your signs and symptoms.
• Urine tests. Your urine may be tested for evidence of blood, protein or other abnormalities to determine if your kidneys are still working properly.

Biopsies

People who have Henoch-Schonlein purpura often have deposits of a certain protein, IgA (immunoglobulin A), on the affected organ. Your doctor may take a small sample of skin so that it can be tested in a lab. In cases of severe kidney involvement, your doctor may suggest a kidney biopsy to help guide treatment decisions.

Imaging tests

Your doctor may recommend an ultrasound to rule out other causes of abdominal pain and to check for possible complications, such as a bowel obstruction.