Candidosis, a new challenge

Abstract

Superficial candidosis is a common fungal infection that could become a gateway to systemic spread. Candida albicans is the most important Candida spp; recently, so-called emergent species, such as C dubliniensis, C famata, and C lipolytica have been isolated. This chapter describes the clinical manifestations and laboratory diagnostic techniques, including direct examination, smears, cultures, and physiologic tests. Topical antifungal drugs available for the treatment of superficial candidosis, including imidazoles, triazoles, allylamines, and nystatin, are also discussed. For granulomatous and invasive forms of candidosis, triazoles, allylamines (terbinafine), echinocandins (caspofungin), and amphotericin B are elective therapeutic choices. It is important to eliminate associated predisposing factors that contribute to infection and, if possible, all samples obtained should be evaluated for cases of resistance.

Introduction

Mycoses have recently shown an important increase in their incidence because the general population is more exposed to factors that favor mycosis infection. Many times, these predisposing factors are related to immunodeficiency. In the case of candidosis, these include treatment with antibiotics, steroids, cytostatic, and immunodepressant drugs; organ and bone marrow transplantation; diabetes; leukemia, lymphoma, and other types of cancer; AIDS; and malnutrition. Candidosis is the emerging mycosis that has the greatest effect due to its frequency and the severity of its complications.

Superficial candidosis is one of the most common clinical forms. It is characteristically chronic and recurrent, and at times, indicates the beginning of severe forms of this mycosis.¹ One of the problems in clinical practice is the over-diagnosis or under-diagnosis of this infection, which leads to therapeutic errors.

Laboratory diagnostic techniques for candidosis can frequently produce false-positive or false-negative results if the appropriate method is not applied. In many instances, when traces of Candida yeast are observed or isolated on the skin or in the secretions being analyzed, laboratories report a positive result without taking into consideration that this yeast is a normal element of the flora of the skin and mucous membranes.

The treatment of this mycosis is another important challenge. Despite new and more effective antimycotic drugs, therapies often fail because of ignorance regarding doses and therapeutic regimes or because of its increasing resistance to antifungal drugs. Therefore, antifungal sensitivity studies should be undertaken, when possible, before antifungal therapy is started.