Schönlein-Henoch purpura is classified as follows:
Palpable (palpable) purpura (small-spotted capillary hemorrhage in the skin, subcutaneous tissue, or mucous membranes) or petechiae (pinpoint hemorrhage of the skin or mucous membranes; considered an obligatory criterion), predominantly of the legs plus one of the following criteria (sensitivity (percentage of diseased patients in whom the disease is detected by use of the procedure, ie. i.e., a positive finding occurs) 100%, specificity (probability that actually healthy individuals who do not have the disease in question are also detected as healthy in the test) 87%):
- Abdominal pain – diffuse acute onset, colicky.
- Possible further manifestation:
- Invagination (invagination of a part of the intestine into the aborally following part of the intestine).
- Melena (blood in the stool)
- Possible further manifestation:
- Histopathological (fine tissue):
- Typical leukocytoclastic vasculitis with predominantly IgA deposits or proliferative glomerulonephritis with predominantly IgA deposits.
- Arthritis (joint inflammation) or arthralgia (joint pain) – acute onset.
- Renal involvement (kidney involvement)
- Proteinuria (increased excretion of protein in urine: > 0.3 g/24 h) or > 30 mmol/mg of albumin/creatinine ratio in spontaneous morning urine
- Hematuria (blood in the urine) or erythrocyte cylinder (> 5/facial) or erythrocytes (red blood cells) ≥ 2 + in the urine stix.
According to the ACR* criteria, Schönlein-Henoch purpura is considered confirmed when two of the following criteria four criteria are met:
- Palpable (palpable) purpura
- Age of manifestation <20 years
- Intestinal colic
- Histological evidence of granulocytes (belonging to the white blood cells) in the vascular wall of arterioles (small arteries located behind the arteries and in front of the capillaries in the bloodstream)
* American College of Rheumatology (ACR)
