Fungal infections of the skin are caused mainly by two groups of fungi: dermatophytes, such as Trychophyton rubrum, which invade keratin (e.g. hair, skin and nail tissue) and yeasts, such as Candida albicans, which infect warm, moist sites.
Superficial dermatophyte infections, such as ringworm, athlete’s foot and groin infection, can be treated with over-the-counter antifungal agents. Dermatophyte infections of the scalp and hands require systemic treatment, as do widespread infections of the trunk. Nail infections affecting a small number of nails may respond to topical treatment but extensive nail infections also require systemic treatment.
Opportunistic yeast infections (Candida species) represent a smaller group but can be important in diabetic and immunocompromised patients. Pityriasis versicolor is a harmless, but often distressing condition that is easily treated with OTC products – see box below.
The effectiveness of treatments depends on good adherence and persistence, in addition to other measures to minimise the growth of fungal organisms and prevent reinfection. This means that there is much for the pharmacy team to do in terms of educating and encouraging patients to get the best out of their treatments.
Pityriasis versicolor
Pityriasis versicolor is caused by the proliferation of the yeast Malassezia furfur, also known as Malassezia ovale, which is part of the normal flora of human skin. Usually Malassezia species grow sparsely in the seborrhoeic areas of the scalp, face and chest without causing a rash.
Hot, humid conditions favour overgrowth of the organism. Superficial patches with fine scales (‘pityriasis’ means bran-like scale) appear pink or fawn on untanned skin, but look pale on tanned skin.
Pityriasis versicolor can be treated with topical imidazole antifungal creams such as clotrimazole, miconazole, econazole and ketoconazole.