Onychomycosis: Laboratory Methods

  • Mahmoud GhannoumEmail author
  • Nancy Isham


Onychomycosis is caused by dermatophytes, and to a lesser extent by non-dermatophyte moulds (NDMs), and Candida spp. It is important to identify the causative agent of each case of onychomycosis in order to provide the proper management, which includes antifungal therapy, possible physical debridement, and expectant prognosis. This chapter provides guidelines for the proper collection of nail specimens for direct smear and culture. Additionally, various methods for performing direct examinations of clinical material are included, as well as descriptions of both conventional laboratory methods and molecular assays for identifying these fungal species. In cases of treatment failure, it is also important to have a means of determining an infecting organism’s susceptibility to available antifungals. Various susceptibility assays, including broth microdilution and agar diffusion, are compared. Finally, the importance of proper laboratory diagnosis of onychomycosis to the success of clinical trials of novel antifungals is discussed, with an emphasis on the role of negative microscopy in the definition of mycological cure.


API Calcofluor Candida albicans ChromAgar Dermatophytes DTM Germ tube Hair perforation Inhibitory mould agar KOH MALDI-TOF MS Mycological cure Mycosel Non-dermatophyte moulds PAS PCR Potato dextrose agar Susceptibility Trichophyton agars 


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© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Center for Medical Mycology, University Hospitals Cleveland Medical Center and Case Western Reserve UniversityClevelandUSA

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