Особливості місцевого лікування оніхомікозів

Анотація

Recently, the incidence of onychomycosis has been increasing. This is facilitated by poor nutrition, poor personal hygiene, decreased immunity, and changes in the body’s immune reactivity. Systemic therapy carries a risk of adverse and toxic effects. Local therapy has several advantages, the main one being minimal side effects. The antifungal agent is applied directly to the affected nail plates and is rapidly absorbed. The concentration of the antifungal agent in the lesion is sufficient to suppress the activity of pathogenic fungi. The use of topical drugs during and after systemic therapy can reduce its duration and prevent recurrence. Topical treatment begins with mechanical removal of the affected portion of the nail plate and the use of keratolytic agents (e.g., urea and salicylic acid). Local antifungal drugs include azole derivatives. They disrupt ergosterol biosynthesis by inhibiting the conversion of lanosterol to ergosterol through inactivation of the enzyme 14α-demethylase, resulting in a fungistatic effect. Allylamines inhibit squalene epoxidation and its conversion to lanosterol by inactivating the enzyme squalene epoxidase. This leads to ergosterol deficiency in the cell membrane and accumulation of the toxic substance squalene in fungal cells, causing their death. Antifungal nail lacquers include terbinafine, amorolfine, and ciclopirox. Amorolfine inhibits two fungal enzymes – delta-14-reductase and delta-7-8-isomerase – involved in ergosterol biosynthesis. This results in the accumulation of toxic metabolites such as squalene and desmethylsterol, leading to fungal cell death. Ciclopirox accumulates in fungal cells at high concentrations, damages the fungal cell wall, disrupts the functions of mitochondria and ribosomes, and blocks the transport of potassium ions, phosphates, and amino acids, ultimately leading to fungal death. Despite the long duration of treatment, local therapy for onychomycosis remains a safe and affordable approach to treating fungal nail infection. Timely initiation of treatment and regular procedures significantly increase the chances of complete recovery of the nail plate and prevention of reinfection.