Combination of a triple wavelength (650 nm, 810 nm, and 915 nm) class IV laser system and local mechanical abrasion in the treatment of chronic toenail onychomycosis: an uncontrolled prospective pilot study

BACKGROUND: Toenail onychomycosis is a frequent fungal infection that is difficult to treat, especially in elderly patients. Diverse local and systemic antifungal treatments are available with variable results. Recently, different laser systems have been proposed for the treatment of onychomycosis, among them a class IV laser system adopting three different wavelengths, that is, 650, 810, and 915 nm (K‐Laser Cube 3TM). OBJECTIVES: This prospective pilot study aims to clarify the clinical, histopathologic, and cultural mycological efficacy of the combination of a triple wavelength laser system and local mechanical abrasion in the treatment of toenail onychomycosis. METHODS: Eight treatment sessions were performed involving a mechanical drill of the friable nail material followed by the laser treatment with four 2‐minute cycles per nail with a median power of 3 W providing 240 J each. Clinical exam, mycological culture, and histopathology with PAS staining of nail clips were performed at the beginning and the end of the treatment period. RESULTS: Nine patients with 16 clinically involved nails were included in this study (median age: 55.6). Clinical improvement was noted in eight patients (89%) at the end of the treatment cycles. Initial positive cultures could be reduced from six (67%) to two (22%), P = 0.07, while histopathologic examination by PAS staining remained invariable positive in all patients (100%). CONCLUSION: Despite clinical improvement, the combination of this laser treatment and mechanical abrasion could not reduce the fungal infection rate in affected toenails. Additional local or systemic antimycotic agents should be combined in order to avoid expected clinical recurrences.