Shiitake mushroom-induced flagellate erythema: A striking case and review of the literature.

Ingestion of raw or undercooked shiitake mushrooms is associated with a distinctive flagellate erythema. We describe a 61-year-old Caucasian man who presented with a pruritic, erythematous eruption of multiple linear streaks on the trunk and extremities starting 1 day after eating raw shiitake mushrooms. His symptoms and skin lesions resolved with minimal hyperpigmentation within approximately 1 week after treating with topical steroids and oral antihistamines. Skin biopsy showed non-specific findings, including a sparse perivascular and interstitial dermatitis as well as focal vacuolar interface changes. Our case illustrates that this condition is a visibly striking dermatitis with a self-limited course. The pathomechanism of the skin eruption remains unclear.