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Onychomycosis and the Diagnostic Significance of Nail Biopsy
Author(s) -
Grover Chander,
Reddy Belum Siva Nagi,
Chaturvedi Krishnamoorthy Uma
Publication year - 2003
Publication title -
the journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 65
eISSN - 1346-8138
pISSN - 0385-2407
DOI - 10.1111/j.1346-8138.2003.tb00358.x
Subject(s) - nail (fastener) , onycholysis , direct examination , medicine , histopathology , nail disease , nail plate , dermatology , pathology , biopsy , pemphigus vulgaris , paronychia , materials science , political science , metallurgy , law
Onychomycosis is the most common cause of deformed nails. It is often confused clinically with other nail diseases such as psoriasis. A cross sectional study was carried out in 120 clinically suspected onychomycosis patients to assess the diagnostic utility of nail unit histopathology. The majority of the patients were males (72.5%) in the age group of 20–40 years (55%). Involvement of fingernails alone (37.5%) was found to be more common than toenails (12.5%). Distal and lateral subungual onychomycosis [DLSO] (76.6%) was the predominant morphological type noted. Direct microscopy with 10% potassium hydroxide (KOH) preparation revealed fungal filaments in 82.5% of the cases. Mycological culture on Sabouraud's dextrose agar with and without cycloheximide indicated fungal isolates in 44% of the cases, with Trichophyton mentagrophytes being the most common isolate (38.3%). The combined approach with KOH preparation and culture showed the evidence of fungus in 103 cases (85.8%). Of the rest of the 17 cases in whom both these procedures failed to confirm a diagnosis, nail unit biopsy was carried out in 15 consenting patients. Fungal hyphae (better demonstrable on PAS staining) were evident in 14 cases (93.3%). Other histopathological features observed among these patients were subungual hyperkeratosis, neutrophilic infiltrate, parakeratosis, hemorrhage, and serum crusts. We concluded that histopathological examination of nails is a valuable diagnostic aid in onychomycosis, especially if routine parameters fail to establish a diagnosis.