RESUMEN
Scleritis and episcleritis are rare ocular inflammatory diseases but deserve to be known by internists because of their frequent association with systemic autoimmune diseases. It is important to distinguish them between because their prognosis, therapeutic management and potential complications are very different. Episcleritis represents a superficial ocular inflammation with usually benign visual prognosis, no complication with local treatment, and is associated with a systemic autoimmune disease in rare cases. In contrast, scleritis is a potentially serious ophthalmological condition that can threaten the visual prognosis in the absence of appropriate systemic treatment. It is associated with an underlying disease in 40-50% of cases, in particular a systemic autoimmune disease (25-35% of cases) or an infectious cause (5-10% of cases). Rheumatoid arthritis and systemic vasculitides, particularly antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides, are the main autoimmune causes of scleritis and episcleritis. Scleritis can reveal the underlying autoimmune disease and requires systematic etiological investigations. Aggressive, complicated, refractory forms or those associated with a systemic autoimmune disease require glucocorticoids or even immunosuppressants, and close collaboration between ophthalmologists and internists is required. The development of biologic agents offers new effective therapeutic tools in the management of these difficult cases.