Generalized interstitial granuloma annulare--response to adalimumab.

BACKGROUND: Cause and pathogenesis of granuloma annulare are poorly understood. A foreign-body granuloma formation induced by an unknown inciting antigen is suspected. Generalized forms often coincides with recalcitrant progression and frustrated experimental therapies.

METHODS: We report a case of generalized interstitial granuloma annulare resolving completely after treatment with adalimumab. An initial dose of 80 mg was administered subcutaneously followed by a maintenance dose of 40 mg every two weeks.

RESULTS: Already after two weeks, the eruptions became less infiltrated and paled. After a follow up of 7 weeks, only a residuum of postinflammatory hyperpigmented maculae without infiltration presented. The initially affected body surface area of over 35% reduced to less than 5%. Histopathological examination revealed a significant reduction in the interstitial histiocytic infiltration and the precipitations of mucin.

CONCLUSION: Although adalimumab should not be first line therapy for granuloma annulare, our case showed that it may profit well-selected patients and shorten disease duration.