Efficacy of long‐term intralesional triamcinolone in Morbihan's disease and its possible association with mast cell infiltration

Morbihan's disease is characterized by chronic persistent facial edema of the upper half of the face, absence of typical diagnostic findings, and refractoriness to treatment. A 44‐year‐old man was diagnosed with Morbihan's disease based on clinical signs and histopathology, which showed dermal edema in upper dermis, discrete lymphocytic infiltrate without granulomatous reaction, and mast cell infiltration. After long‐term therapy with intralesional triamcinolone a remarkable objective and subjective clinical response was observed. Reported cases of Morbihan's disease are reviewed, with respect to their treatment and histopathological findings. Mast cell infiltration has been observed on histopathology in most patients who responded to intralesional triamcinolone, suggesting a possible marker of response. The long‐lasting response seen in our case indicates the efficacy of intralesional triamcinolone in this rare condition.