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Skin infections

Fungi case challenge 2

Scaly heel

A man complains he has itchy feet.

Which terms best describe the morphology of the skin rash? # Vesicles # Pustules #! Scaling || Flaking skin due to an increase in the dead cells on the surface of the skin (stratum corneum). # Fissures

Discoloured nails

He is concerned about the appearance of his toenails.

Which terms best describe the morphology of the toenail dystrophy? #! Subungual hyperkeratosis || Scaling under the distal nail plate #! Onycholysis || Distal nail separated from nail bed #! Yellowing || Yellow discolouration may or may not be due to fungal infection # Pincer nail Fungal microscopy of the feet and toenails is positive. What is (are) the most appropriate diagnosis (diagnoses)? #! Tinea pedis # Athlete's foot #! Tinea unguium #! Onychomycosis Explanation: The images show a scaly heel, an appearance suggesting a non-inflammatory tinea pedis, and onychomycosis, resulting in yellowed toenails, mild onycholysis and subungual hyperkeratosis. What is the likely organism? *! _Trichophyton rubrum_ * _Microsporum canis_ * _Candida albicans_ * _Trichophyton tonsurans_ Explanation: Tinea pedis and onychomycosis are generally due to T. rubrum, T. interdigitale or E. floccosum, though rarely a mould may be responsible. M. canis causes inflammatory tinea and rarely invades the nail plate. T. tonsurans is an anthropophilic dermatophyte fungus that causes tinea capitis. The patient is treated with an oral antifungal agent for 3 months. Which of the following may be suitable? # Nystatin #! Itraconazole #! Terbinafine # Amphotericin-B Explanation: The correct responses are itraconazole and terbinafine. Oral nystatin is not absorbed systemically. Amphotericin-B is very toxic and only used for serious systemic fungal infections.