Henoch-Schönlein purpura (HSP), first recognised by Heberden in 1801, is a systemic, IgA mediated vasculitis of small vessels that is usually self-limiting but may progress to gastrointestinal bleeding, intussusception, and nephropathy. A third of patients will experience recurrences.¹ Currently treatment is confined to rest, analgesia, and steroids for refractory abdominal pain,² and immunosuppressants for complications, especially renal disease. Original reports, predominantly in adults, show that the symptoms of purpuric rash, abdominal pain, and arthritis in HSP respond to treatment with dapsone.^3–,⁵

Even though the first case of HSP treated with dapsone was reported in 1983, it is still not generally recognised as a treatment for HSP. We describe eight children in whom, because of the severity or persistence of their symptoms, treatment with dapsone was commenced from among 41 patients diagnosed with HSP from January 1992 to May 2004. All gained a clinical response from treatment with the most beneficial effect on the skin rash. The demographic characteristics of the patients and their presenting clinical features as well as treatment are shown in table 1⇓. The rash improved within 3 days to 1 week of starting treatment with dapsone in all patients. Six of eight relapsed when treatment was stopped, but responded again to treatment. The side effects are dose related and uncommon at doses commonly used (1–2 mg/kg daily).

Dapsone, an antileprotic drug, used for a variety of dermatological conditions, appears to be of special value in diseases characterised by accumulation of neutrophils, notably with leucocytoclastic vasculitis, of which HSP is an example. There is evidence that it has antioxidant scavenger effects and may suppress the generation of toxic free radicals in neutrophils. It also inhibits prostaglandin D2 production and synthesis of IgG and IgA antibodies.⁶ It may also inhibit IgA–neutrophil interactions.³ Given the pathogenesis of HSP with IgA mediated vasculitis, treatment with dapsone represents an exciting form of treatment. The clinical course of our patients suggests that dapsone controls the cutaneous vasculitis rather than cures it. As steroids may mask the features of more ominous intestinal disease, dapsone can be a reasonable alternative. Nonetheless, to date there is no evidence of a positive effect on renal disease.

In conclusion, dapsone is a drug that may have a role in the treatment of HSP. In order to establish its usefulness it is necessary to conduct a multicentre, placebo, randomised controlled trial.

Informed consent was obtained from parents before starting treatment with dapsone.