A survey among dermatologists: diagnostics of superficial fungal infections – what is used and what is needed to initiate therapy and assess efficacy?

Abstract

Background Superficial fungal infections are common. It is important to confirm the clinical diagnosis by mycological laboratory methods before initiating systemic antifungal treatment, especially as antifungal sensitivity and in vitro susceptibility may differ between different genera and species. For many years, the gold standard for diagnosis of superficial fungal infections has been direct fungal detection in the clinical specimen (microscopy) supplemented by culturing. Lately, newer molecular based methods for fungal identification have been developed. Objective This study was initiated to focus on the current usage of mycological diagnostics for superficial fungal infections by dermatologists. It was designed to investigate whether it was necessary to differentiate between initial diagnostic tests and those used at treatment follow‐up in specific superficial fungal infections. Methods An online questionnaire was distributed among members of the EADV mycology Task Force and other dermatologists with a special interest in mycology and nail disease. Results The survey was distributed to 62 dermatologists of whom 38 (61%) completed the whole survey, 7 (11%) partially completed and 17 (27%) did not respond. Nearly, all respondents (82–100%) said that ideally they would use the result of direct microscopy (or histology) combined with a genus/species directed treatment of onychomycosis, dermatophytosis, Candida‐ and Malassezia‐related infections. The majority of the dermatologists used a combination of clinical assessment and direct microscopy for treatment assessment and the viability of the fungus was considered more important at this visit than when initiating the treatment. Molecular based methods were not available for all responders. Conclusion The available diagnostic methods are heterogeneous and their usage differs between different practices as well as between countries. The survey confirmed that dermatologists find it important to make a mycological diagnosis, particularly prior to starting oral antifungal treatment in order to confirm the diagnose and target the therapy according to genus and species.

Malassezia-Associated Skin Diseases, the Use of Diagnostics and Treatment

“…Different sampling methods have been used to confirm the presence of Malassezia yeasts in skin conditions and these include tape stripping, skin scraping, swabs, and contact plates (Darabi et al, 2009). Direct microcopy is used frequently in clinical settings (Saunte et al, 2018) as it can be used to detect fungal elements after application of potassium hydroxide and adding a dye such as e.g., Parker ink, methylene blue, lactophenol blue, May-Grunwald-Giemsa, Gram staining or a fluorescence dye such as Calcofluor white and Blancophor (Rubenstein and Malerich, 2014;Tu et al, 2018). Malassezia is Abbreviations: AD, atopic dermatitis; M, Malassezia; HND, Head and neck dermatitis; PCR, Polymerase Chain Reaction; PV, pityriasis versicolor; SD, seborrheic dermatitis.…”

“…For this reason during the last five decades molecular based methods (Arendrup et al, 2013) as well as methods that identify the chemical imprint of the different species e.g., different Polymerase Chain Reaction (PCR) techniques, Matrix Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF) mass spectrometry (Kolecka et al, 2014;Diongue et al, 2018;Honnavar et al, 2018;Saunte et al, 2018) and or Raman spectroscopy (Petrokilidou et al, 2019) have been applied to achieve fast and accurate fungal identification.…”

Nail Disease: Clinical Decisions among Portuguese Dermatologists and Family Physicians

“…The clinical signs of onychomycosis are often difficult to distinguish from other causes of nail dystrophy [3]. Laboratory confirmation of a clinical diagnosis with identification of the causal organism should be obtained before starting treatment as the efficacy of oral and topical therapies can be species dependent [2-4]. Several methods can be used to confirm the diagnosis: direct microscopy using potassium hydroxide, periodic acid-Schiff staining of nail clippings, fungal culture, and molecular diagnostic methods such as PCR have recently been developed [1].…”

Influence of the cultivation medium and pH on the pigmentation of Trichophyton rubrum

“…Therefore the diagnosis of the fungal infections involves in many cases microscopic examination and fungal cultivation. According to a survey among dermatologists, direct microscopy was the most important diagnostic tools followed by cultivation of the pathogen [1]. Whereas direct microscopy is often sufficient to detect a fungal infection, the identification of the pathogen requires in most cases fungal cultivation.…”