Henoch-Schonlein purpura (HSP)
What is HSP?
- Henoch-Schonlein purpura (HSP) is a form of blood vessel inflammation, or vasculitis.
- HSP affects the small arterial vessels in the skin, gastrointestinal tract and frequently the kidneys.
- The disease occurs primarily in children between 3 and 8 years of age.
- Boys are slightly more affected than girls.
What are the symptoms of HSP?
- HSP results in a purple, sometimes raised, skin rash, most prominent over the buttocks and behind the lower extremities (see photo called Henoch-Schonlein purpura). This is caused by red blood cells that leak out of the damaged blood vessels.
- Lesions in areas of pressure (eg, from socks or elastic bands) may produce a pattern similar to the pattern of whatever is producing the pressure on the skin.
- Infants tend to have more involvement of the face and scalp with accompanying swelling.
Joint inflammation (arthritis):
- Two thirds of affected children have arthritis.
- The joints most frequently affected with pain and swelling are the ankles and the knees.
- Usually this only lasts from 1-3 days in the individual joints.
- Cramping pain in the abdomen is usually seen in 2/3 of affected children, but loss of appetite, diarrhea, vomiting and occasional blood in stools can be seen.
- Rarely, patients develop an abnormal folding of the bowel called intussusception.
- 50% of patients have kidney inflammation but less than 1 in 10 have permanent injury to the kidneys.
- Inflammation of the blood vessels in the kidneys can cause blood or protein in the urine.
Other: Boys can also develop painful scrotal swelling.
How long can the symptoms last?
- Symptoms usually last between 2 – 12 weeks, typically about a month.
- Recurrences are not frequent but do occur.
What causes HSP?
- HSP frequently follows a viral or streptococcal infection.
- HSP seems to represent an unusual reaction of the body’s immune system which is in response to the infection.
- HSP occurs throughout the year, but some studies have shown that there is an increase in cases during the fall and winter months.
Who is affected by HSP?
- HSP is the most common acute vasculitis affecting children, with an incidence of approximately 10 cases per 100,000 children per year.
- Although the syndrome is usually seen in children, people of any age may be affected.
- It is more common in boys than in girls.
How is HSP diagnosed?
- The diagnosis of HSP is based on a combination of factors, including a physical examination that reveals skin lesions and joint tenderness, urinalysis that shows microscopic blood in the urine, stool that shows microscopic blood, skin biopsy (usually not needed to diagnose) showing vasculitis, and lab tests to rule out alternative diagnoses.
How is HSP treated?
- While HSP is generally a mild illness that resolves spontaneously, it can cause serious problems in the kidneys and bowels.
- Joint pain can be relieved by tylenol or by anti-inflammatory medications, such as ibuprofen.
- There has been controversy regarding the efficacy of steroid use; however, a recent meta-analysis was published by Weiss et al in the journal Pediatrics which concluded: Corticosteroids, given early in the course of the illness, seem to produce benefits for several major clinically relevant Henoch-Schönlein purpura outcomes, such as significant abdominal pain.
What is the prognosis?
- The prognosis for patients with HSP is generally excellent.
- Nearly all patients have no long-term problems. The kidney is the most serious organ involved when it is affected. Rarely, patients can have serious long-term kidney damage.
Butani L, Morganstern, BZ. Long-term outcome in children after Henoch-Schonlein purpura nephritis. Clin Pediatr. 2007;46:505-511.
Dillon MJ. Henoch-Schönlein purpura: recent advances. Clin Exp Rheumatol. 2007;25(1 suppl 44):S66-S68.
Weiss PF, Feinstein, JA, Luan, X, et al. Effects of corticosteroid on Henoch-Schönlein purpura: a systematic review. Pediatrics. 2007;120:1079-1087.