Unequivocal morphological diagnosis of fungi in morphologically abnormal nails

Nail biology and nail science

The nail plate is the permanent product of the nail matrix. Its normal appearance and growth depend on the integrity of several components: the surrounding tissues or perionychium and the bony phalanx that are contributing to the nail apparatus or nail unit. The nail is inserted proximally in an invagination practically parallel to the upper surface of the skin and laterally in the lateral nail grooves. This pocket-like invagination has a roof, the proximal nail fold and a floor, the matrix from which the nail is derived. The germinal matrix forms the bulk of the nail plate. The proximal element forms the superficial third of the nail whereas the distal element provides its inferior two-thirds. The ventral surface of the proximal nail fold adheres closely to the nail for a short distance and forms a gradually desquamating tissue, the cuticle, made of the stratum corneum of both the dorsal and the ventral side of the proximal nail fold. The cuticle seals and therefore protects the ungual cul-de-sac. The nail plate is bordered by the proximal nail fold which is continuous with the similarly structured lateral nail fold on each side. The nail bed extends from the lunula to the hyponychium. It presents with parallel longitudinal rete ridges. This area, by contrast to the matrix has a firm attachment to the nail plate and nail avulsion produces a denudation of the nail bed. Colourless, but translucent, the highly vascular connective tissue containing glomus organs transmits a pink colour through the nail. Among its multiple functions, the nail provides counterpressure to the pulp that is essential to the tactile sensation involving the fingers and to the prevention of the hypertrophy of the distal wall tissue, produced after nail loss of the great toe nail.

Efficacy of debridement alone versus debridement combined with topical antifungal nail lacquer for the treatment of pedal onychomycosis: a randomized, controlled trial

Pedal onychomycosis is a common malady caused by dermatophytes, saprophytes, and yeasts. Traditional treatment options for this condition include toenail debridement, and pharmacological therapies that range from the application of topical agents to the oral administration of antifungal medications. In this study, 55 patients (289 toenails) were randomly allocated to either nail debridement (27 [49.09%] patients) or debridement plus application of topical antifungal nail lacquer (28 [50.91%] patients). The primary outcome was mycological cure, and secondary outcomes included foot-related quality of life, and a number of clinically important toenail characteristics. After a median follow-up of 10.5 months (range, 3.25-14.25) months), patients in the antifungal nail lacquer group improved statistically significantly more than did those in the debridement alone group, and displayed a 76.74% rate of mycological cure. None of the patients in the debridement-only group experienced mycological cure. Variables that statistically significantly decreased the likelihood of cure included yeast on culture, pedal hyperhidrosis, cigarette smoking, involvement of the lunula, and involvement of >50% of the transverse width of the nail. Variables statistically significantly associated with an increased likelihood of cure included intervention before 6 months' duration, treatment at a large, urban practice, black race, and loss of protective sensation.

LEVEL OF CLINICAL EVIDENCE

1.