Dermatophytosis (Tinea) and Other Superficial Fungal Infections

Abstract

Superficial dermatophyte infection has been reported under a variety of different terminologies since the early days of recorded human civilization (1). However, it has only been during the past 200 years with the development of modern science that the contagious nature of the disease could be related to the presence of fungal organisms (1). The current taxonomy of dermatophytes used today, dividing organisms into Trichophyton,Microsporum, and Epidermophyton species, was not developed until 1934 (1). Topical preparations have been the historic method of treatment for dermatophyte infections. The first effective oral medication for dermatophytes, griseofulvin, was not developed until 1958 (1). Thus, although the term “tinea” used for dermatophyte infection has ancient roots (1), the current standards of medical treatment for dermatophyte infection are a recent development, and the field continues to develop as more fungal knowledge and more effective therapies become available. Dermatophytes require keratin for growth and therefore infect hair, nails, and superficial skin, with clinical manifestations named for the area affected: tinea capitis (scalp); tinea corporis (body); tinea cruris (groin); tinea pedis (feet); tinea manuum (hands); tinea barbae (affecting the beard area, in males); tinea faciei (face); and tinea unguium (nails) (2). Tinea infections have alternately been called “ringworm,” because of the lesions that present as a circular or oval clearing surrounded by a red, scaly, elevated border (“ring”). Tinea unguium is the subset of onychomycosis infections caused by dermatophytes, as opposed to nail infections caused byCandida or nondermatophyte moulds. Besides the dermatophytoses, superficial infections may also result from infection with other fungi, including the Malassezia species of yeast. Malassezia feed on lipids found in areas where sebaceous gland activity is highest and in individuals with high levels of sebaceous secretions. Although first recognized as a pathogen in 1846, laboratory culture was not successful until it was recognized that the organisms had a lipid requirement, in 1927 (3). Initially only two species were described, under the genus