Shiitake Flagellate Dermatitis

Abstract

A man in his early 70s presented with a 3-day history of intensely pruritic erythematous papules and papular vesicular eruption arranged in a flagellate pattern on his neck, trunk, (Figure 1), and extremities with no general symptoms. On questioning, he had eaten undercooked shiitake mushrooms 2 days before the onset of the cutaneous lesions. Laboratory investigation was unremarkable. A skin biopsy revealed spongiosis, marked papillary dermal edema, and a dermal perivascular inflammatory infiltrate mainly composed of lymphocytes and eosinophils.