Trends in the treatment of dermatophytosis

©2000 Revista Iberoamericana de Micología Apdo. 699, E-48080 Bilbao (Spain) The management of dermatophytosis begins with topical agents. These agents should penetrate the skin and remain there in order to suppress the fungus. In the last 50 years numerous drugs have been introduced for the treatment of superficial infections. The choice of treatment is determined by the site and extent of the infection, the species involved as well as by the efficacy and safety profile, and kinetics of the drugs available. For localised non-extensive lesions caused by dermatophytes topical therapies with an imidazole, allylamines, tolnaftate, morpholine derivates, etc is generally used. For tinea unguium, scalp ringworm, extensive dermatophytosis, or skin lesions with folliculitis, systemic antifungal treatment is necessary. The rational treatment of dermatophytosis requires mycological confirmation (KOH and culture); in other words the clinician should confirm a presumptive clinical diagnosis of dermatophyte infection before the start of treatment. Since spontaneous healing of dermatophytosis is uncommon, treatment implementation is necessary. Dermatophytes are located in the stratum corneum within the keratinocytes. The signs and symptoms that appear in infected individuals are due to acute and chronic inflammatory changes that appear in the dermis. For these reasons, antifungal agents should have the ability to penetrate the stratum corneum cells to be efficient when applied topically. The vast majority of antifungals are fungistatic with the concentrations achieved in the skin when applied topically; the growth of dermatophytes is delayed and these are shed with the skin renewal and healing is achieved. The antifungal agents and the components incorporated on the vehicle should be non-irritant and well tolerated. The vast majority of antifungals are applied twice daily, although the latest ones introduced are applied only once daily. Attention is currently being directed towards shortening the course of therapy and applying the medication once daily in an attempt to increase patient compliance and it is generally advisable to prolong treatment for two weeks once clinical cure is achieved. Skin lesions located on face, trunk and limbs usually require two or three weeks of treatment. Inflammatory dermatophyte infections of the feet should be treated for four or six weeks and hyperkeratotic lesions of palms and soles are best treated with oral antifungals since they are usually unresponsive to topical antifungals. According to WHO (World Health Organisation), the dermatophytes are defined as a group of molds that form three genera: Epidermophyton, Trichophyton and Microsporum [1]. They comprise about 40 different species, and have common characteristics: