CO₂ Laser-Assisted Nail Sampling for Mycological Testing in Onychomycosis

Onychomycosis is the most common nail infection, predominantly caused by Trichophyton spp., and is divided into four main types. Confirmatory testing is crucial, but obtaining an adequate sample may be challenging. We suggest the use of carbon dioxide (CO₂) laser for painlessly detaching the nail plate during mycological examination and ensuring a sufficient specimen.

We retrospectively enrolled 25 patients with distolateral onychomycosis, treated according to the following protocol: (1) multiple passes of CO₂ laser at 10 W in continuous mode along the proximal border of the affected nail plate; (2) the nail plate was gently cut; (3) the nail bed was curetted; (4) subungual debris and plate fragments were collected for KOH test and culture.

The mean visual analog score (VAS) for pain experienced during the procedure was 0.7 (SD: 2.1), indicating that the sampling was relatively painless for the majority of patients. There were no permanent changes observed in the nail unit of any patients during the follow-up visits as a result of using the CO₂ laser.

We firmly believe that the use of lasers offers numerous advantages, including ease of use, reduced pain perception, and the ability to target the proximal margin of fungal infections where viable hyphae are significantly represented.