Abstract: 【Abstract】 Three cases of flagellate shiitake mushroom dermatitis caused by Pleurotus ostreatus, Auricularia auricula, and Flammulina velutipes respectively were reported. Case 1, a 45-year-old male patient, developed multiple flagellate erythematous patches and papules on the trunk, axillae and abdomen without any subjective discomfort 8 hours after ingestion of a large amount of grilled Pleurotus ostreatus. Case 2, a 33-year-old female patient, developed multiple flagellate erythematous patches with mild swelling and itching on the back 1.5 days after consuming a fresh Auricularia auricula salad, and millet-sized papules were densely distributed on the erythematous patches. Case 3, a 54-year-old female patient, developed cord-like, flagellate edematous erythema and papules on the neck, trunk and proximal extremities 72 hours after consuming Flammulina velutipes. Histopathological examination of the dorsal lesions in case 3 showed epidermal spongiosis, intraepidermal blisters, papillary dermal edema, superficial dermal vasodilation, erythrocyte extravasation, inflammatory infiltration composed mainly of lymphocytes around dilated blood vessels, and a few scattered eosinophils. The 3 patients were all diagnosed with flagellate shiitake mushroom dermatitis. Case 1 received no treatment, while cases 2 and 3 were symptomatically treated with topical fluticasone propionate ointment, and achieved recovery of skin lesions after 1 week.

Key words: Dermatitis, Phytodermatitis, Lentinan, Auricularia, Flammulina velutipes