Concealing Meets Healing in the Treatment of Toenail Onychomycosis: A Review of Concurrent Nail Polish Use With Topical Efinaconazole 10% Solution

Introduction: Females are more likely than males to seek help or treatment for onychomycosis and are more likely to camouflage affected nails with nail polish. Between 2016 and 2022, over half of prescriptions for topical efinaconazole 10% solution were written for females, suggesting that there may be particular interest in the interaction between nail polish use concurrent with efinaconazole treatment for onychomycosis. Methods: Review in vitro data on effects of nail polish on nail penetration of efinaconazole 10% solution and clinical studies on the impact of nail polish use on efficacy of topical efinaconazole in the treatment of toenail onychomycosis. Results: Only 4 small studies have assessed interactions between efinaconazole 10% solution and concurrent nail polish use. In vitro, penetration of efinaconazole 10% solution through cadaverous human nails coated with traditional nail polish was similar to penetration through uncoated nails. In a 1-year clinical study, once-daily efinaconazole treatment for 48 weeks was associated with improvements in onychomycosis severity and clear toenail growth that were similar for participants who used traditional nail polish and those who did not use nail polish. In a second, 6-month clinical study, participants received once-daily efinaconazole treatment concurrent with monthly gel nail polish pedicures. After 6 months, 100% of participants tested negative for fungal infection (mycological cure) and all participants experienced visible improvements in their treated toenails. In clinical and in vitro studies, efinaconazole application was associated with degradation of traditional nail polish texture and appearance as well as color transfer to the applicator and unused medication. In contrast, efinaconazole did not affect the duration, quality, or texture of gel nail polish. Conclusions: Application of nail polish did not prevent penetration of efinaconazole 10% solution through human nails or its successful use in the treatment of toenail onychomycosis. Further, efinaconazole did not impact the texture or appearance of gel-polished nails. To our knowledge, these findings represent the only available data on topical treatment of toenail onychomycosis with concurrent nail polish use, and may be of particular importance when selecting treatment options for female patients with onychomycosis. Funding: Ortho Dermatologics