60 51歲陳小姐，近一個月發現右側頭皮有局部脫髮，頭皮搔癢、脫皮並且產生疼痛之區塊，之前醫院醫師給予之抗生素及抗發炎之prednisone並沒有改善狀況。於是醫師詳細問診後才知道：陳小姐3個月前撿到一隻很可愛的流浪犬，取名波比。波比很活潑討喜，經常與陳小姐親近，醫師於是以伍氏燈（Wood’s light）檢查呈陽性，進一步取患部皮屑培養；結果養出白色毛狀菌落，顯微鏡觀察呈現分隔菌絲（septate hyphae），產生數量眾多之梭形、厚壁、表面粗糙之大孢子（macrospores）。最可能之感染病原是下列何者？

Epidermophyton floccosum Microsporum canis

Microsporum gypseum Trichophyton schoenleinii

B

Wood's lamp is a diagnostic tool used in dermatology by which ultraviolet light is shone (at a wavelength of approximately 365 nanometers) onto the skin of the patient;

Fungal and bacterial infections

It is also helpful in diagnosing:

• fungal infections (Microsporum audouini). Some forms of tinea, such as Trichophyton tonsurans, do not fluoresce.^[1]

• bacterial infections (Corynebacteriium minutissimum is coral pink, Pseudomonas is yellowish-green)^[2]

• Propionibacterium acnes, the bacteria responsible for acne, exhibits an orange glow under a Wood's lamp.^[3]