Expert Panel Review of Skin and Hair Dermatophytoses in an Era of Antifungal Resistance

Abstract

Dermatophytoses are fungal infections of the skin, hair, and nails that affect approximately 25% of the global population. Occlusive clothing, living in a hot humid environment, poor hygiene, proximity to animals, and crowded living conditions are important risk factors. Dermatophyte infections are named for the anatomic area they infect, and include tinea corporis, cruris, capitis, barbae, faciei, pedis, and manuum. Tinea incognito describes steroid-modified tinea. In some patients, especially those who are immunosuppressed or who have a history of corticosteroid use, dermatophyte infections may spread to involve extensive skin areas, and, in rare cases, may extend to the dermis and hair follicle. Over the past decade, dermatophytoses cases not responding to standard of care therapy have been increasingly reported. These cases are especially prevalent in the Indian subcontinent, and Trichophyton indotineae has been identified as the causative species, generating concern regarding resistance to available antifungal therapies. Antifungal-resistant dermatophyte infections have been recently recognized in the United States. Antifungal resistance is now a global health concern. When feasible, mycological confirmation before starting treatment is considered best practice. To curb antifungal-resistant infections, it is necessary for physicians to maintain a high index of suspicion for resistant dermatophyte infections coupled with antifungal stewardship efforts. Furthermore, by forging partnerships with federal agencies, state and local public health agencies, professional societies, and academic institutions, dermatologists can lead efforts to prevent the spread of antifungal-resistant dermatophytes.

Fig. 1

Trichophyton tonsurans tinea corporis on the ventral forearm (Dr. Avrom Caplan)

Fig. 2

Anterior groin of a male patient with Epidermophyton floccosum tinea cruris (CDC/Dr. Lucille K. Georg)

Fig. 3

Tinea corporis on the lower leg (species unknown) with co-occurring fungal folliculitis (Dr. Avrom Caplan)

Fig. 4

Trichophyton mentagrophytes tinea capitis in the scalp of a Black child (CDC)

Fig. 5

Microsporum tinea capitis (CDC)

Fig. 6

Trichophyton schoenleinii favus accompanied by alopecia (CDC/Dr. Libero Ajello)

Fig. 7

Trichophyton schoenleinii mentagrophytes tinea barbae (CDC/Dr. Lucille K. Georg)

Fig. 8

Tinea faciei of unknown species involving the ear (CDC)

Fig. 9

Trichophyton concentricum tinea imbricata on the back of a child in Papua New Guinea (CDC/K. Mae Lennon, Tulane Medical School; Clement Benjamin)

Fig. 10

Interdigital tinea pedis of unknown species (CDC/Dr. Lucille K. Georg)

Fig. 11

Tinea pedis (Dr. Shari Lipner)

Fig. 12

Tinea manuum (Dr. Avrom Caplan)

Fig. 13

Tinea corporis of the back in a transplant recipient (Dr. Avrom Caplan)

Fig. 14

Tinea corporis of the distal leg in a transplant recipient (Dr. Avrom Caplan)

Fig. 15

Trichophyton indotineae KOH preparation (Dr. Avrom Caplan). KOH potassium hydroxide