Topical tacrolimus in granuloma annulare and necrobiosis lipoidica

Sir, Necrobiosis lipoidica (NL) and granuloma annulare (GA) are noninfectious granulomatous skin disorders, and usually have a chronic course that is difficult to treat. The aetiology of both skin diseases is still unknown, but immunological factors have been implicated. A possible aetiology of GA is a hypersensitive immune reaction of delayed type IV with release of cytokines and consequent degranulation of lysosomal enzymes that cause tissue damage.1, 2 The central relevance of the immunological pathogenesis of GA and NL is also confirmed by good treatment experience with immunomodulating and immunosuppressive drugs.3–5 Glucocorticosteroids are potent immunomodulatory agents, but their long‐term use in patients with GA and NL is limited by systemic and local side‐effects.6 The new immunosuppressant class of macrolides is a possible effective alternative to steroids in the treatment of inflammatory skin diseases, acting through a nonsteroidal pathway. Tacrolimus ointment is a novel topical macrolide immunosuppressant, in which topical application appears to be a safe new option due to the low number of side‐effects.7, 8 Recent studies suggest that tacrolimus does not cause skin atrophy. We report our treatment experience with topical tacrolimus in four patients histologically diagnosed as having GA and two with NL. All patients were treated with tacrolimus ointment 0·1% twice daily for 8 weeks. The objective of the study was to assess the value of tacrolimus in treating these conditions.