Comparison of plain potassium hydroxide mounts, fungal cultures and nail plate biopsies in the diagnosis of onychomycosis.
OBJECTIVE
To compare the relative sensitivity of direct microscopy, fungal culture and nail plate biopsy in the diagnosis of onychomycosis.


METHODS
Cross-sectional study.


METHODS
The Skin Department, Military Hospital, Rawalpindi from February 1998 to February 1999.


METHODS
A total of 50 patients who were suffering from different clinical variants of onychomycosis, irrespective of their age, gender, with or without simultaneous presence of systemic diseases, were subjected to laboratory investigations including direct microscopy with 20% potassium hydroxide (KOH) for fungal hyphae, fungal cultures and nail plate biopsies. These patients were later categorized into two groups based upon the results of nail plate biopsies.


RESULTS
Of 50 patients, 15 (30%) were positive for fungal elements in direct microscopy, 8 (16%) were positive for fungal culture and 16 (32%) revealed positive results in nail plate biopsies. Amongst nail plate biopsy positive cases, 10 (63%) were positive for direct microscopy and 6 (37.5%) were positive for fungal cultures. In biopsy negative cases, positive results for direct microscopy were seen in 5 (14.7%) patients and positive fungal culture was found in 2 (5.88%) patients.


CONCLUSIONS
The clinical impression of onychomycosis is not true in all the cases. Nail scraping for direct microscopy with 20% KOH should be the first line screening test for all patients which should then be supplemented with fungal culture and/ or nail plate biopsy.
Malik
Naveed Akhter
NA
Department of Dermatology, Armed Forces Hospital, Sharourah, KSA. naveedmalik467@hotmail.com
Nasiruddin
Dar
Nasser Rasheed
NR
Khan
Ashfaq Ahmed
AA
D001706:Biopsy; D003430:Cross-Sectional Studies; D003877:Dermatitis, Contact; D005260:Female; D006801:Humans; D006878:Hydroxides; D025301:Hyphae; D008297:Male; D009262:Nails / Q000473:pathology; D014009:Onychomycosis / Q000175:diagnosis* / Q000382:microbiology; D017680:Potassium Compounds
D006878:Hydroxides; D017680:Potassium Compounds; C029943:potassium hydroxide