Methods for Diagnosing Onychomycosis

Cost-effectiveness of diagnostic tests for toenail onychomycosis: A repeated-measure, single-blinded, cross-sectional evaluation of 7 diagnostic tests

“…Most studies report positivity rates without reference to a ''gold standard''; some of these studies are summarized in Table I. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] The sensitivities of these tests are affected by practitioner experience, specimen collection methodology, and clinical onychomycosis pattern. [22][23][24] The purpose of this study was to estimate and compare the cost-effectiveness (utilizing sensitivity as the unit of effectiveness) of the most commonly used diagnostic tests: potassium hydroxide (KOH) alone (interpreted by a laboratory technician [KOH-LAB] and by a dermatologist [KOH-CLINIC]), KOH with dimethyl sulfoxide (KOH-DMSO) or chlorazol black E (KOH-CBE), culture with dermatophyte test medium (DTM), 25 culture with Mycobiotic and Inhibitory Mold Agar (Cx), and histopathologic analysis using periodic acideSchiff staining (PAS).…”

A modified approach to the histologic diagnosis of onychomycosis

“…1 In addition to having poor sensitivities, both fungal cultures and KOH mounts are time consuming. Nail biopsies (including nail clippings) have been shown to be a valuable adjunctive tool for diagnosing onychomycosis and have been shown to detect dermatophytes missed by microscopic examination of KOH mounts and nail cultures.…”

“…1-3 Nail clipping examination with PAS stain has been reported to have a sensitivity of 85%. 1 Our prior experience at the New York University Dermatopathology Section has shown that nail plate processing in plastic-embedded medium is very efficacious for the histologic diagnosis of onychomycosis. However, it is technically difficult, costly, and time consuming.…”

“…It has been reported that histologic examination with periodic acideSchiff (PAS) stain of nail clippings is the most sensitive diagnostic test for onychomycosis. 1 Processing nail plates for histologic examination is technically demanding and potentially very time consuming.…”

Successive mycological nail tests for onychomycosis: a strategy to improve diagnosis efficiency

“…However, when only one sample is analyzed, the frequency of false-negative results is very high. Other laboratory methods, such as ungual biopsy, PCR, flow cytometry and immunohistochemical techniques, have been used to improve onychomycosis diagnosis; however, these methods are not usually available in common dermatology centers [1,[21][22][23]. As a viable alternative in such labs, we investigated whether serial repetition of routine direct microscopy examination and fungal culture improves diagnosis efficacy.…”