Big toenail onychomycosis features associated with response to 1064 nm Nd: YAG laser treatment

Background: A few studies discussed the factors correlated to response in laser treatment of onychomycosis. Objective: This study aimed to seek big toenail onychomycosis features that correlate with response to 1064 nm Nd: YAG laser treatment. Methods: This single-center, retrospective study included patients who had only one big toenail onychomycosis, with a confirmed mycological diagnosis and/or a high clinical suspicion. Patients had three sessions 1 month apart. The following characteristics were collected from the patients' files: age, sex, smoking and arterial hypertension statuses, results of baseline mycological culture, Onychomycosis Severity Index (OSI) score at baseline and at the end of the 6-month follow-up, as well as the reported side effects. Results: We included 105 patients, 86 women and 19 men, with a mean age of 43 years. Demographics have shown that 73.6% of patients were smokers, 17.9% had arterial hypertension, 61.9% had a culture positive for Trichophyton species, and 9.4% had a culture positive for Candida species. According to the OSI score, onychomycosis was mild in 18.9%, moderate in 39.6%, and severe in 41.5% of patients. At 6 months, clinical cure was achieved in 57.1% of patients. Conclusion: The OSI decrease after 3 sessions of Nd: YAG laser was significantly more important in women and in patients with positive mycology culture, smaller affected area of the nail, no subungual hyperkeratosis, and no nail matrix involvement. Age, smoking, hypertension, and side effects were not shown to significantly correlate with the decrease of the OSI score.