Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Onychomycosis laboratory findings
Introduction
Overview
Overview
Laboratory findings consistent with the diagnosis of onychomycosis include potassium hydroxide smear, culture and histology.
Laboratory findings
Laboratory findings
If all nails are affected then fungal infection is improbable. To avoid misdiagnosis as psoriasis, lichen planus, contact dermatitis, trauma, nail bed tumor or yellow nail syndrome, laboratory confirmation may be necessary. The three main approaches are potassium hydroxide smear, culture and histology. This involves microscopic examination and culture of nail scrapings or clippings. Recent results indicate that the most sensitive diagnostic approaches are direct smear combined with histological examination[1] and nail plate biopsy using periodic acid-Schiff stain[2].
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]