Henoch-schonlein purpura (HSP) is a disease of small blood vessels. It is characterized by acute inflammation and leakage of blood from the arterioles, venules and capillaries. This systemic small vessel vasculitis leads to inflammation and bleeding in many parts of the body such as skin, joints, gastrointestinal tract, and kidneys.
Henoch-schonlein purpura predominantly affects children and most characteristic symptom is purple rash on skin usually on legs and buttocks. The disease is rare in adults but when present spontaneous resolution of the symptoms is less common as compared to children. In adults there is greater risk of the disease progressing to renal damage and gastrointestinal problems.
Etiology of HSP is not clear but approximately 50 percent of patients give history of recent upper respiratory tract infections such as common cold etc. Since the disease is benign and self limiting in majority of patients, symptomatic treatment is needed. More aggressive treatment may be needed if the disease involves kidney or gastrointestinal tract.
Causes Of Henoch-Schonlein Purpura
The exact etiology of henoch-schonlein purpura is still unclear. In HSP there is inflammation of tiny blood vessels which causes bleeding in skin, joints, kidney and gastrointestinal tract. Other organs are rarely affected. Researchers are not sure why the initial inflammation develops in the smaller blood vessels.
They believe it to be an abnormal response of the immune system towards some type of trigger, mostly an infection. This they believe because half of the patients give recent history of upper respiratory tract infection before development of henoch-schonlein purpura. Streptococcal sore throat, measles, cold, etc are important upper respiratory tract triggers.
Other suspected triggers implicated are vaccination, certain medicines, insect bites etc. Certain factors increase the risk of developing HSP. It is more common in children but may also occur in adults. Although rare if present in adults, the disease is more aggressive.Adult males and boys are affected more than girls. The condition is seen more in Asian and European population than in African people.
Characteristic Symptoms Of Henoch-Schonlein Purpura
In adults henoch-schonlein purpura is less common. However when present the symptoms may be skin rash or purpura, joint pains, pain in abdomen, blood in urine. Before the actual symptoms, patient may be having history of common cold or upper respiratory tract infection, muscle pain and headache. Generally the organs involved in henoch-schonlein purpura are skin, joints, intestine and kidney.
Following are characteristic symptoms of HSP:
- Skin rash: Patient may have purpura, a critical feature in HSP. It is a type of rash which appears purple and looks like a bruise. There may be several tiny purple spots on skin, mainly in the legs and buttocks. Sometimes purpura may be present on upper body parts on chest, face and arms. Some adults may develop skin ulcers.
- Arthritis: Knee and ankle joint pain and swelling is common in patient with HSP. Often in adults joint pain occurs few days earlier before the appearance of purple spots on skin. Swelling and pain in joints alleviate as the disease gets cured. It does not cause permanent damage to the joints.
- Gastrointestinal symptoms: Many adults suffer from GI tract symptoms such as pain in abdomen, nausea, vomiting, and blood in stool. Bowel obstruction and gastrointestinal bleeding may sometime occur in adults.
- Kidney involvement: Henoch-schonlein purpura can also damage kidney especially in adults there is more risk of kidney involvement. This damage may present as hematuria (blood in urine) and proteinuria (protein in urine). Patient may not realize the passage unless the urine test is performed.
Diagnosis And Treatment Of Henoch-Schonlein Purpura
Henoch-schonlein purpura is mainly diagnosed from the clinical presentation of the patient by the examining doctor. However in adults, skin biopsy, blood test and urine test may be necessary to indentify presence of blood in urine and to know certain structural changes in skin because of the disease.
Henoch-schonlein purpura usually is a self limiting disease. This means the disease gets cured after few weeks without any treatment. In majority of cases only supportive and symptomatic treatment may be necessary. This will help to alleviate the symptoms such as joint pain.
Patient may need analgesic to reduce pain in joints and abdomen. Use of steroids is controversial. Some researchers recommend it while some may avoid. However, steroids may be used in severe form of HSP which involves kidney and causes substantial renal insufficiency. If the condition is severe, even immunosuppressive medicines may be needed.