Clinical Snapshot Shiitake Dermatitis

[摘要] A 70-year-old man presented with an approximately 2-day history of itching striate skin lesions on the trunk and extremities with no general symptoms (Figure). On inquiry, he stated that he had eaten an Asian meal around 2 to 3 days before the onset of symptoms. He had consumed various fungi, including shiitake mushrooms. Shiitake dermatitis is described quite frequently in Asia, and the number of case reports in western countries is constantly increasing. Typically, the consumption of shiitake mushrooms is followed by a delayed striate cutaneous reaction resembling the flagellate dermatitis that can be induced by bleomycin (Latin flagellum: scourge, whip). The skin lesion is thought to represent a toxic reaction to the heat-labile protein lentinan; for this reason, the mushrooms should always be properly cooked before being eaten. Further allergological investigations such as skin tests or determination of specific IgE in serum bring no further benefit. Apart from bleomycin dermatitis, the differential diagnoses, depending on the clinical findings, include drug reactions or contact allergy. The recommended treatment is topical steroids, supplemented with antihistamines if required. The lesions usually resolve without scarring.

[学科分类] 医学（综合）