The use of intermittent itraconazole therapy for superficial mycotic infections: a review and update on the 'one week' approach

Pityriasis versicolor

Pityriasis versicolor is a mild or chronic condition characterized by scaly hypopigmented or hyperpigmented lesions usually affecting the trunk. The lesions vary depending on tropical or temperate climates. The disease seems to occur mainly at adolescence when the sebaceous glands are more active. Malassezia yeasts have been implicated in the pathogenesis of this disease. The mycelial form of the fungus has been suggested to be the cause of lesions. Antifungal preparations have been used to treat the initial presentation effectively, although in a proportion of patients the disease tends to reoccur. They are available in a wide range of formulations and have been shown to be safe.

Pityriasis versicolor

Pityriasis versicolor is a common superficial fungal infection of the skin. It is caused by Malassezia spp., which are normal human saprophytes. Under certain conditions, both exogenous and endogenous, the fungus can convert from a yeast to a pathogenic mycelial form. This alteration results in mild inflammation of the skin, and in characteristic clinical and histological changes. The taxonomy of Malassezia spp. has recently been modified to include six obligatorily lipophilic species, all of which can be found on human skin, plus one non-obligatorily lipophilic species, which only rarely colonizes human hosts.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be aware of the role of Malassezia in the development of pityriasis versicolor, the clinical and histological changes arising from this dermatosis, and the diagnosis and treatment of this disorder.

Current Management of Onychomycosis and Dermatomycoses

Three newer oral antifungal agents, itraconazole, terbinafine and fluconazole, have revolutionized treatment of superficial mycoses. The tissue pharmacokinetics of itraconazole and terbinafine allow much shorter courses of therapy- with higher efficacy-in the treatment of onychomycosis, compared to other oral agents. Itraconazole pulse dosing and terbinafine daily dosing have shown comparable efficacy against dermatophyte onychomycosis; similar itraconazole regimens have been effective against nondermatophyte infections. Refractory clinical patterns of nail disease appear to be more responsive to oral antifungal therapy when combined with adjunctive therapy, such as debridement. These agents are effective against cutaneous dermatophytosis, with shorter treatment regimens. Tinea versicolor may be treated with a single-dose, intermittent, or daily regimen of an oral azole agent, depending on the drug selected. These newer oral antifungal agents have been proven effective against tinea capitis; effective regimens are shorter than those for griseofulvin. The safety profile of these newer agents has been very favorable.