CLINICAL EVALUATION OF A TOPICAL POLY UREA-URETHANE 16% POLYMER ON DYSTROPHIC NAILS: A REVIEW

Onychodystrophy, which is any alteration of nail morphology, describes a wide spectrum of nail disorders caused by either exogenous or endogenous insults. Nail dystrophy may manifest as a misshapen, damaged, infected, or discolored nail unit that may affect the fingernails, toenails, or both. Morphologic terms commonly used to describe these affected nails are onycholysis, onychauxis, and onychorrhexis. Onycholysis is separation of the nail plate from the nail bed and may be caused by exogenous trauma, but also may be caused by a systemic disorder like psoriasis. The pocket created also creates a pathway for dermatophytes to infect the nail bed. Onychauxis is thickening of the nail unit seen both in onychomycosis and psoriasis. Onychorrhexis presents as nail plate ridges parallel to the lateral nail fold. This may be seen as a sign of normal aging or as the manifestation of underlying diseases such as lichen planus and psoriasis. The most common type of nail dystrophy we see as podiatric practitioners is onychomycosis which represents about half of the pathologies seen. 1 Other disorders, such as lichen planus, psoriasis, and trauma can also cause nail dystrophy. Since many nail disorders mimic onychomycosis in clinical presentation, it is imperative for the practitioner to determine the cause of the nail dystrophy prior to treatment. This poster will focus on nail dystrophy caused by dermatophyte infection. Onychomycosis or tinea unguium is caused by invasion of the nail unit by dermatophytes, nondermatophyte molds, and/or Candida albicans. Onychomycotic nails generally are described as onycholytic, discolored, and hyperkeratotic with subungual debris. Clinicians may see concomitant tinea pedis or tinea cruris in patients with onychomycosis. The most common form of onychomycosis on the toenails is distal lateral subungual onychomycosis caused by Trichophyton rubrum. Clinically, it may be difficult to distinguish onychomycosis from other existing nail pathologies. KOH prepration, PAS The efficacy and safety of poly-ureaurethane, 16% was reported in a study by Nasir et al in the Journal of Drugs and Dermatology. 4 This was a prospective, self-controlled, and single arm study of adult patients with KOH and culture confirmed onychomycosis of at least one great toenail. Sixty three (63) healthy adults (aged 18-65) had nails that ranged in 20-65% nail involvement with no lunula involvement [Table 1]. Patients were excluded from the study if the nail was thicker than 3 mm or had an uncontrolled medical condition that would decrease circulation to the lower extremity. The investigational product, poly-ureaurethane, 16%, was a polymeric suspension that formed a uniform film when applied to the nail. The polymer product was dispersed in organic solvents that vaporized rapidly upon application which allowed the suspended polymer to adhere to the contours of the nail to form a flexible, waterproof barrier over the nail. The film is colorless, transparent, and possesses good moisture vapor permeability. Subjects in the trial applied the product once daily to the affected great toenail at bedtime during the week, but had a product holiday over the weekend. Nail hygiene had to be maintained, with clean and debrided nails. They were instructed to allow the product to dry thoroughly before donning socks or any other garment. Establishment of a diagnosis of dermatophyte (Trichophyton or Epidermophyton species) involvement was completed at baseline, and then follow up KOH and fungal cultures were done at visit labeled 1 month (one month after treatment began), 3 months, and 6 months. Trichophyton rubrum was the most commonly cultured organism at baseline. In addition to fungal scrapings performed at each visit, any adverse events (AEs) and visual assessment of the treated target toenail were documented. Visual assessment parameters included notation of improvement, no change, or deterioration of the following: color, nail involvement, onycholysis, thickness, and subungual hyperkeratosis [Table 2].