In recent years, the arrival of new, highly effective agents for the eradication of onychomycosis has dramatically changed the clinician’s approach to patient care. In particular, several new oral antifungal agents have proven to be very useful in the treatment of onychomycosis. Because such therapies may carry with them significant expense and the potential for adverse side effects, it is important for the diagnosis of onychomycosis to be accurate, prompting treatment only in instances where there is the potential for definite patient benefit.
Traditionally, culture techniques using various types of specialized media have been the most commonly used methods for the diagnosis of onychomycosis. In the office setting, potassium hydroxide (KOH) preparations also have been useful for clinicians, with rapidity as their main benefit. Histologic analysis of nail plate biopsies, or surgical pathology diagnostic testing (SPDT), is yet another method to establish the diagnosis of onychomycosis. Although these various techniques have their distinct advantages, comparisons that assess their usefulness in the clinical setting are lacking in the literature. The relative sensitivity, specificity, and cost-effectiveness of culture techniques as compared to KOH preparations and SPDT have not been tested adequately. The purpose of this study was to determine the relative usefulness of SPDT as compared with KOH preparations and standard culture techniques for the identification of onychomycosis. The sensitivity of each test in the detection of fungal elements was recorded. In addition, the ability of each test to detect specific fungal elements (ie, hyphal and yeast forms) was determined.
Eugene McCoy and William Velez for preparation of high-quality microscopic slides; Martha Castro, Bruno Jean, Farnoosh Ebrahimi, and Raquel Solorzano for outstanding microbiology work.
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