[Necrotizing scleritis and recurrent erythema nodosum: a diagnostic challenge].

The necrotizing scleritis and recurrent erythema nodosum, two clinical entities difficult to diagnose and which represent a challenge to the physician. Tuberculosis produces both processes by an immune reaction of delayed hypersensitivity type IV to various antigenic components of mycobacteria. Most tuberculosis patients have no ocular history of pulmonary or systemic disease in up to 50 % and no evidence of pathology in the chest radiograph.