膿疱性乾癬様皮疹を呈したMicrosporum canisによる急性汎発性浅在性白癬

・ほぼ全身にびまん性に紅色丘疹と小膿疱が多発し，膿疱性乾癬を思わせる皮疹を呈し，一見して白癬とは考えられずに診断に苦慮した．

・生毛部のKOH検査で毛外性小胞子菌性寄生を認め，真菌培養にてMicrosporum canis（M. canis）が分離され，飼いネコからも同様の菌が得られたことから飼いネコから感染したM. canis感染症と診断した．

・合併症のない患者にステロイドが誤用されたために誘発された，急性汎発性浅在性白癬の1例を経験し，繰り返しKOH検査を行うことの重要性を改めて痛感した．

（「症例のポイント」より）

　

Acute generalized superficial trichophytosis caused by Microsporum canis, mimicking generalized pustular psoriasis

　

Yokoyama, Kae1）Kimura, Utako1）Kurihara, Mana1）Hiruma, Masataro3）Takamori, Kenji2）Suga, Yasushi1）

1）Department of Dermatology, Juntendo University Urayasu Hospital

2）Juntendo University

3）Ochanomizu Institute for Medical Mycology and Allergology

　

A 30-year-old man presented with generalized pustular psoriasis-like eruptions, comprising red papules and small pustules. Initial KOH examination yielded negative results；however, his symptoms worsened, and he developed fever after using topical steroids. Microscopic examination of the hair revealed hyphae and spores on the exterior surface of the hair shaft. Microsporum canis was isolated by mycological culture. We report a case of acute generalized superficial trichophytosis induced by misdiagnosis and incorrect treatment. When unusual and treatment-resistant rash is observed, repeating KOH examination is important