Early-onset granulomatous arthritis, uveitis and skin rash: characterization of skin involvement in Blau syndrome.

Skin involvement in BS is the earliest clinical manifestation of the BS in the large majority of patients. The recognition of dermatological manifestations as granulomatous skin lesions and early dermatological expertise are the key to an early diagnosis of BS. In view of our results, it seems reasonable to propose a simplified view of skin lesions of BS in which the granuloma is the key structure.