Flagellate Dermatitis After Ingestion of Shiitake Mushrooms in a Healthy Female Living in the Southeastern United States.

BACKGROUND: Shiitake flagellate dermatitis is a shiitake mushroom (SM)-induced toxic dermatosis that is a widely recognized clinical phenomenon in Japan, China, and Korea but is rarely reported outside of Asia. Typically, 24-48 hours after consumption of SM, patients develop severely pruritic, linear, often parallel, infiltrated erythematous lesions, commonly described as being in a "whip-like" pattern. The dermatosis is noted preferentially on the trunk, extremities, and neck. Shiitake flagellate dermatitis is self-limited and typically resolves within days to weeks of its appearance.

CASE REPORT: A healthy 36-year-old woman living in the southeastern United States presented with a 48-hour history of pruritic, truncal, morbilliform, flagellate-like efflorescences that extended to her buttocks and thighs. Her hard and soft palates, palms and soles, hair-bearing scalp, and face were also involved. Two days before presentation, the patient ate a store-bought salad preparation that contained raw mushrooms including SMs. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Shiitake dermatitis has a characteristic whip-like pattern that, if identified early by first-line physicians, can relieve concerns for more serious etiologies and expedite appropriate therapy.