Indications and efficiency of dapsone in IgA vasculitis (Henoch-Schonlein purpura): case series and a review of the literature

Immunoglobulin A (IgA) vasculitis (Henoch-Schonlein purpura (HSP)) is the most common vasculitis in children. It is characterized by purpuric rash, arthritis, gastrointestinal, and/or renal involvement. Spontaneous resolution is the typical outcome. In chronic cutaneous manifestations of IgA vasculitis, dapsone seems to show a good effectiveness. Multiple case reports and case series about dapsone in chronic IgA vasculitis are available. However, no clear evaluation of its indications, its effectiveness, or its usage guidelines (optimal dosage or duration of treatment) is available. We reviewed the published cases of IgA vasculitis treated by dapsone and compared them with 2 similar cases that we encountered. Seventeen patients (ranging from 22months old to 16years old) with severe or persistent clinical signs of IgA vasculitis were included. Dapsone showed good results on the resolution of cutaneous lesions but not on renal manifestations. Complications (methemoglobinemia) were observed on 1 patient. Half of the patients relapsed after treatment discontinuation. The difference between the time lapse before initiation and the duration of the treatment was not significant.Conclusion: We suggest that dapsone can have a positive effect in chronic IgA vasculitis when cutaneous manifestations last more than 6weeks at the dosage of 1-2mg/kg once per day during 1week.