A clinical diagnosis of fungal nail infection (onychomycosis) can be made without the need for microbiological sampling. https://cks.nice.org.uk/topics/fungal-nail-infection/
Topical agents are recommended as first line therapy. Should this fail, we then recommend sampling to confirm the diagnosis prior to commencing second line (systemic) therapy. Please ensure appropriate clinical details are added to samples, those without clinical details will be rejected.
Skin Scrapings, Hair, Nail Clippings
Microscopy & Culture. Diagnosis of fungal infection
A) Distal subungual infection (The commonest form of infection):
• Clip the distal portion of the nail to expose the abnormal material under the nail plate.
• Using a small curette, dental scraper, blunt scalpel or scissor blade, firmly scrape under the nail plate until the crumbling white degenerating portion is reached, discard the superficial material
• Scrape the keratin debris directly onto a black collection card (Dermapak). This makes it easier to see how much material has been collected
• If the nail is onycholytic it should also be possible to scrape some keratinous material from the underside of the nail clippings
• Do not send large pieces of nail clipping
B) Proximal subungual onychomycosis:
Pare down the normal surface of the nail plate at the lunula and collect the white debris from the deeper portion of the plate onto a Dermapak.
C) White superficial onychomycosis:
Scrape the white spots on the nail and discard the outermost surface material; scrape some of the underlying white debris onto a Dermapak.
D) Candida infection:
The material closest to the proximal and lateral nail edges should be obtained. If Candida onycholysis is suspected, the lifted nail bed and, if necessary, the under surface of the nail plate are scraped.
Tested at RDE
Please note 30-50% of specimens with positive microscopy are negative on culture in any laboratory
Microscopy available within 48 hours. Culture available 2-3 weeksSpecimen Labelling Procedure