Total agranulocytosis caused by dapsone therapy for tuberculoid leprosy--an unappreciated serious side effect of anti-leprosy treatment with clinical implications.

Dapsone-induced agranulocytosis is a rare but potentially fatal adverse effect of treatment for tuberculoid leprosy. Publications distributed by the WHO Leprosy Elimination Campaign for patient information on leprosy do not contain any advice or guidelines for post-dapsone therapy follow-up. As a result of this major deficiency, the local anti-leprosy campaign in Sri Lanka has no such guidelines on dapsone therapy for leprosy patients. We report two patients with total agranulocytosis caused by dapsone therapy for tuberculoid leprosy including one fatality. As leprosy is more prevalent in developing countries such as Sri Lanka, we recommend that WHO publications on patient information should include post-dapsone therapy follow-up guidelines to avoid such catastrophes which are undetected until the patients are critically ill.