Flagellate Erythema: A Case of Shiitake Dermatitis and Review of Pathogenesis

Shiitake dermatitis is a rare eruption that is associated with the ingestion of uncooked shiitake mushrooms, resulting in a distinctive flagellate erythema. It was initially hypothesised that the mechanism of disease related to a toxic reaction to lentinan; however, recent evidence has suggested a potential allergic mechanism. The authors herein present a case of shiitake dermatitis and review the current understanding of pathogenesis of this condition and flagellate morphology. With an increase in consumption of shiitake mushrooms in Western society, shiitake dermatitis is expected to become more prevalent worldwide.