Novel in vivo observations of luliconazole 5% nail solution for onychomycosis: An ultrastructural study

Lesional nails of 10 patients with onychomycosis (tinea unguium) were investigated by transmission electron microscopy (TEM) to gain an insight into in vivo morphological changes of dermatophytes after application of a clinical dosage of topical luliconazole (LLCZ) 5% nail solution. In these cases, Trichophyton rubrum (T. rubrum) was identified in three cases and T. interdigitale was identified in four cases (three unidentified cases; we were unable to identify either the genus or species). Specimens from tinea unguium before and after topical LLCZ application (maximum of 14 days) were observed by TEM. Two types of morphological changes of hyphae were revealed. Intracytoplasmic degeneration without antecedent obvious changes in the cell wall (type 1 degeneration) and degeneration of the fungal cell wall preceding intracytoplasmic changes (type 2 degeneration) were observed. We also examined in vivo morphological changes of dermatophytes in tinea pedis treated with ketoconazole (KCZ) to compare the morphological changes in the cell wall, plasma membrane, and cytoplasm to those after the application of LLCZ. Intracytoplasmic degeneration (type 1 degeneration) was observed in tinea pedis scales treated with topical KCZ. We confirmed that topical LLCZ 5% nail solution had acting points on the plasma membrane, cell wall, and cytoplasm of dermatophyte hyphae and that various degrees of morphological changes in lesional nails of tinea unguium occurred during treatment with topical LLCZ 5% nail solution.