Also known as Anaphylactoid purpura.
Henoch-Schönlein purpura (HSP) is a disorder that causes inflammation and bleeding in the small blood vessels in your skin, joints, intestines and kidneys.
The most striking feature of Henoch-Schonlein purpura is a purplish rash, typically on the lower legs and buttocks. Henoch-Schonlein purpura can also cause abdominal pain and aching joints. Rarely serious kidney damage can occur.
HSP can affect people of any age, but the majority of cases occur in children under 10.
The medical term for inflammation of the blood vessels is vasculitis. Blood vessels throughout the body become irritated and swollen, which can cause problems such as bleeding into the skin (resulting in a rash) and occasionally problems affecting the kidneys and bowel.
HSP is not usually serious and most cases get better within a few weeks.
The four main characteristics of Henoch-Schonlein purpura include:
Skin Rash (purpura). that looks like small bruises or reddish-purple spots, usually on the buttocks, around the elbows and on the legs, and sometimes also on the face and upper body, are the most distinctive and universal sign of Henoch-Schonlein purpura. The rash develops mainly on the buttocks, legs and feet, but it can also appear on the arms, face and trunk and may be worse in areas of pressure, such as the sock line and waistline.
Swollen, sore joints (arthritis). People with Henoch-Schonlein purpura often have pain and swelling around the joints — mainly in the knees and ankles. Joint pain sometimes precedes the classical rash by one or two weeks. These symptoms subside when the disease clears and leave no lasting damage.
Gastrointestinal symptoms. Many children with Henoch-Schonlein purpura develop gastrointestinal symptoms, such as abdominal pain, nausea, vomiting or bloody stools. These symptoms sometimes occur before the rash appears.
Kidney involvement. Henoch-Schonlein purpura can also affect the kidneys. In most cases, this shows up as protein or blood in the urine, which you may not even know is there unless you have a urine test done. Usually this goes away once the illness passes, but in a few cases, kidney disease may develop and even persist.