A modified approach to the histologic diagnosis of onychomycosis

Modified PAS stain: A new diagnostic method for onychomycosis

“…10 The keratin biopsy described by Chang et al is a technique in which the subungueal hyperkeratosis is analyzed in the same way a skin biopsy is, and better results are reported (97% of positivity) when compared with a PAS stained nail clipping biopsy. 3,9,10,13 The limitations for our diagnostic procedure are that this method requires a histopathology department, a qualified histology technician, and a trained observer. The quality of the sample will also determine the sensitivity and specificity of the test.…”

“…These are excellent methods but not easy to perform. 3 Diagnostic accuracy is important because oral antimycotic treatment is lengthy, expensive and significant drug interactions can occur. The currently employed methods do not offer enough specificity and sensitivity for the diagnosis.…”

An improved method of surgical pathology testing for onychomycosis

“…15 However, the hard keratin of the nail plate makes surgical pathology testing technically difficult and time demanding. 1,7,10 Pretreatment with agents to soften the nail plate have been described, including potassium hydroxide (KOH), 5% trichloroacetic acid and 10% formalin, 10% Tween40, and chitin-softening solutions containing mercuric chloride. 1,12,14,16,17 NaOH at 10% concentration has been used in clinical practice for chemical matrixectomy of ingrown toenails.…”

“…1,7,10 Pretreatment with agents to soften the nail plate have been described, including potassium hydroxide (KOH), 5% trichloroacetic acid and 10% formalin, 10% Tween40, and chitin-softening solutions containing mercuric chloride. 1,12,14,16,17 NaOH at 10% concentration has been used in clinical practice for chemical matrixectomy of ingrown toenails. [18][19][20] Treatment of nail specimens with a strong base such as NaOH causes alkaline hydrolysis of disulfide bonds that bind keratin intermediate filaments in the nail, leading to softening.…”

Onychomykose – ein Update

“…In einer Studie an der New York University wurden über 8 Monate alle unter dem Verdacht auf OM eingesandten Nagelproben histologisch untersucht, insgesamt ließ sich bei 66 Patienten eine OM nachweisen [8]. Bei 97% fanden sich Hyphen im subungualen Material.…”