Nail fungus infection or onychomycosis is an infectious disease and a relatively common pathology.The prevalence of nail lesions in all countries of the world ranges from 18 to 45%.Onychomycosis often occurs in older people, cancer patients and patients with diabetes mellitus, Kaposi's sarcoma and ichthyosis.
Onychomycosis is not only a cosmetic problem.It poses a serious threat to the human body, because the products (xanthomegnine, viomellein, substances such as antibiotics and penicillin) of the vital activity of the fungus lead to long-term persistence in the affected nails and can lead to the development of hepatopathy, drug-induced toxicoderma.
Etiology and epidemiology
The causative agents of onychomycosis are represented by three groups of fungi:
- Dermatophytes (up to 95%) - Trichophyton rubrum (causes damage to the nails of the toes and hands, as well as the skin), trichophytonmentagrophytes (affects the nails of the first and fifth toes)
- Yeast fungi (up to 4%) - Candida spp.(first affects the skin around the nail, and then penetrates the nail plate itself);
- Mold (up to 1%) - Fusarium and Alternaria (most often found in immunodeficiency).
Isolated onychomycosis is rare;Often, simultaneous lesions of the skin of the feet, scalp and smooth skin are observed.
Infection occurs through household items: bathroom rugs, slippers, towels, manicure accessories;as well as when visiting a bathhouse, sauna, or swimming pool.Men are more susceptible to this pathology than women.Most adults suffer from onychomycosis;Among children, cases of nail mycosis are rare.
Risk groups include housekeepers, military personnel, athletes, people who frequently visit bathhouses and saunas, and miners.
The source of infection is the skin of the feet of the infected person;Sometimes the whole family is affected.
Pathogenesis
Onychomycosis is a source of fungal infection that can cause sensitization of the body.In addition, mushrooms release substances that are poisonous to the human body.
Predisposing factors for infection are injuries to the skin of the feet and nails that occur when the toes are squeezed by tight shoes;the humid and warm environment created by some low-quality shoes made of non-natural materials;The presence of severe diseases, immunodeficiency conditions, old age.
Disease symptoms
Based on the difference in symptoms, four forms of onychomycosis are distinguished:
- Distal lateral (subungual) onychomycosisthe most common.The causative agents are Trichophyton Red, Candida and, very rarely, mold.With this type of lesion, the fungus in the nail bed enters the skin through the free edge of the nail and spreads towards the matrix.In this case, the nail plate, due to hyperkeratosis, gradually moves away from the bed and takes on a yellowish color.Thickening of the nail plate may occur, and bacterial contamination gives the nails various colors from greenish to dirty brown.
- Superficial white onychomycosisOften caused by trichophyton mentagrophytes, which causes the formation of white spots on the surface of the nail plate;As the process progresses, these spots merge.This type of onychomycosis occurs in elderly patients with leg deformities, where one leg covers the adjacent one.The nail plate becomes dystrophic, collapses, and is gray or brownish in color, but the matrix and epithelium of the bed are not affected, and there is no inflammatory phenomenon from the skin either.
- Proximal subungual onychomycosisThe rarest type in which the pathogen, most often red trichophyton, penetrates the nail plate from the skin or from the periungual fold, then spreads along it and reaches the matrix and the distal part of the nail plate.As a result, extensive detachment of the nail plate is observed.With secondary bacterial contamination, the nail plate changes color.
- Total dystrophic onychomycosisdevelops as a distal lateral or, less frequently, proximal subungual complication, and also occurs in chronic subcutaneous candidiasis.With this form, the entire nail is affected with its complete destruction;Nail folds are either absent or pathologically thickened, while a normal nail plate cannot be formed.
All onychomycosis should be distinguished from psoriasis, eczema, lichen planus and other skin diseases.To confirm the diagnosis, it is necessary to conduct microscopy of pathological material from the lesion and pathogen culture on special identification media.
Onychomycosis treatment
When prescribing treatment for patients with onychomycosis, several factors must be taken into account: the type of pathogen, the prevalence of the process, the general condition of the patient and his financial capacity.
- Local agents are often used in the treatment of distal and lateral subungual onychomycosis when no more than 3 nails are affected, as well as in patients for whom antimycotic tablets are contraindicated.The most effective topical preparations include creams and varnishes.They are often combined to achieve a faster therapeutic effect.This preparation contains a high concentration of active ingredients;They work effectively on the surface of the nail plate, but cannot always penetrate the nail bed, where the most persistent fungus is located.In such cases, the affected nail plate is removed either surgically or with the help of special chemicals - keratolytics, and local treatment continues.This method is only troublesome because of the length of the process, as it requires careful adherence to the treatment regimen throughout the time during which a healthy nail plate grows.In this case, the ointment should be used every day, and the varnish only once a week.
- Systemic therapy is more effective and reliable in the treatment of onychomycosis;It is used when local treatment fails.Indications for prescribing systemic drugs are the final stages of fertile and proximal-distal onychomycosis, as well as total onychomycosis.
The choice of drugs for systemic treatment must be justified, taking into account the pharmacokinetics, spectrum of action, and antifungal activity of each drug.It should not be forgotten that any drug can provide a clear therapeutic effect if prescribed adequately.