Editors

PekkaLahdenne

Henoch-Schönlein Purpura

The disease most commonly affects children between 2 and 10 years of age. Purpuric skin changes caused by vasculitis are typical symptoms.
Articular symptoms, abdominal pains and haematuria or proteinuria also often occur.
Patients who, in addition to the typical skin changes, have mild abdominal and/or articular symptoms but no haematuria or proteinuria can be treated by a general practitioner.

The vasculitis is common and is often preceded by a bacterial or viral upper respiratory tract infection.
Papules that develop into petecchias appear most commonly on the lower extremities and buttocks (pictures 1 2 3 4).
Extensive periarticular swelling and tenderness may be observed in the ankles and knees, and sometimes also in wrists and elbows. Three patients out of four have articular symptoms.
Abdominal pain occurs in about half of the patients. About 10% of the patients have severe colicky pains.
Almost half of the patients have haematuria and/or proteinuria during the disease. Overt nephritis is rare, and occurs at a later stage of the disease.
Basic investigations include complete blood count, CRP, throat culture, antistreptolysin titre, anti-streptococcal DNase antibodies and a urine dipstick test.

Consider another disease if
- the patient has a fever exceeding 38.5°C
- the plasma CRP concentration exceeds 20 mg/l or the ESR is above 35 mm/h
- the platelet count is decreased or anaemia or leukopenia is detected.
Remember that meningococcal sepsis causes petecchias and sometimes also joint symptoms. If the platelet count is low (< 100) the patient may have ITP or a haematological malignancy.

Intestinal intussusception and melena are in rare cases seen as acute complications of the disease, and very rarely bleeding in other parts of the body.

Mild abdominal and/or articular symptoms, no haematuria or proteinuria: paracetamol 15 mg/kg 3 times daily as needed. In addition, possible underlying tonsillitis or sinusitis is diagnosed and treated as necessary. Urine dipstick tests are taken in association with febrile diseases in the following 6 months.
Abnormal finding in a urine test or severe abdominal or articular symptoms: the patient is referred to a specialist. In these cases, prednisolone is started at discretion of the specialist, 1 mg/kg for 2 weeks, then 0.5 mg/kg for 2 weeks and then 0.5 mg/kg every second morning for 1 week.
The treatment of a severe HSP glomerulonephritis is in the responsibility of a paediatric nephrologist.
If there are signs of renal involvement - particularly if they are significant and last for more than one month - the patient's renal function must be followed up throughout life, as the risk of renal failure is significant. All women who had even mild renal symptoms at onset of Henoch-Schönlein purpura should be carefully observed during and after pregnancy.

Ronkainen J, Nuutinen M, Koskimies O. The adult kidney 24 years after childhood Henoch-Schönlein purpura: a retrospective cohort study. Lancet 2002;360:666-670
Jauhola O, Ronkainen J, Koskimies O et al. Outcome of Henoch-Schönlein purpura 8 years after treatment with a placebo or prednisone at disease onset. Pediatr Nephrol 2012;27(6):933-9. [PubMed]