Onychomycosis is infection of toenails and hands by representatives of various classes of pathogenic and conditionally pathogenic fungal microflora. The clinical picture of onychomycosis depends on the cause that caused the mycosis. The nails affected by the fungus change color and transparency, lose smoothness, thicken, become brittle and rough, delaminate, begin to crumble. At the same time, the sub-elbow and periarticular space may remain unchanged or turn red, swell and be affected by secondary pathogenic flora. Onychomycosis is diagnosed clinically, by examination under a Wood lamp, confocal microscopy of scrapings and bakposev. Antimycotic combined therapy.
Onychomycosis is a common fungal nail disease. One or more nails may be involved in the pathological process separately on the fingers of the hands, separately on the legs, mixed variants are also possible. At the same time, onychomycosis of the hands and feet is completely identical clinically. The term onychomycosis was introduced into dermatological practice in 1854. Pathology has no age restrictions, the only age difference is the speed of recovery. There is no gender coloring. The debut of onychomycosis is possible at any time of the year.
The prevalence of the disease is influenced by climatic conditions, which necessitate the long-term wearing of tight warm closed shoes. For example, in Spain, only 1.7% of the population suffers from onychomycosis, in Finland – 8.4%. The incidence is also affected by the social status of patients. According to various authors, from 10% to 20% of the inhabitants of the planet are infected with onychomycosis, in the structure of dermatological pathology, more than a third of all nail plate lesions belong to it. The urgency of the problem lies in the increase in morbidity, the prevalence of pathology among children and the presence of a large number of latently infected patients.
The trigger of pathology is a pathogenic or conditionally pathogenic fungus. The development of onychomycosis is provoked by injuries, flat feet, varicose veins, hyperhidrosis, endocrine and immunological disorders, blood diseases, vascular pathology, prolonged use of hormonal drugs, antibiotics and cytostatics, wearing tight shoes and refusal to comply with generally accepted standards of personal hygiene. The disease does not develop immediately, it is preceded by a lesion of the skin of the soles and palms, and only then the pathogen is introduced into the nail.
On healthy skin, the pathogen gets from infected household items or when shaking hands with an infected person. Together with the corneal cells of the surface layer of the epidermis, containing infectious forms of the existence of the fungus, the pathogenic origin is transferred to clean skin. Then the fungus spreads over the skin when touching the contaminated areas. Colonization of the sub-nail space by a fungus leads to asymptomatic reproduction of the pathogen, its achievement of critical mass and penetration from under the free edge of the nail plate into the horny layers of the nail with any provoking effect (for example, with injury to the nail or periarticular tissues). Once in the nail plate, the fungus multiplies, forming tunnels, passages and channels in the nail tissue. The degree of damage to the nail plate depends on the chemical structure of the nail and on the virulence of the fungus.
The fungus is moving towards the nail bed, while the speed of its progress exceeds the growth rate of the nail plate. Instead of being pushed out of the nail by healthy cells, the fungus reaches the base of the nail, causing pathological changes in both the nail and the bed. Having reached the nail bed, the fungus provokes specific inflammation in the dermis, sensitizes the sub-elbow space, causes nail detachment with hyperkeratosis phenomena. Inflammation also covers the periarticular rollers, which contributes to the additional penetration of the fungus into the nail, in which dystrophic changes occur.
In modern dermatology, there are two working classifications of onychomycosis, one taking into account morphological changes in the nail, the other taking into account the place of occurrence of the pathological process.
Pathomorphologically , there are three varieties of onychomycosis:
- Normotrophic – the natural shape and size of the nail are preserved. The color of the nail plate changes, instead of a monochrome solid, whitish inclusions and lines appear in the lateral sections.
- Hyperkeratotic – the horny plate fades, sub-elbow hyperkeratosis, deforming the nail, prevails, causing pain when walking.
- Atrophic – the horny plate becomes brown, the nail exfoliates from the bed with the phenomena of dystrophy.
According to the place of occurrence , the following forms of onychomycosis are distinguished:
- Surface – the almost unchanged horny plate of the nail is revealed to be opal-white, the inclusions visually resemble powder scattered on the surface of the nail.
- Distal – pathological changes begin with the free edge of the nail.
- Lateral – the process affects one or two lateral surfaces.
- Proximal – the nail is affected at the base of the hole.
- Total – the entire nail surface is affected.
- Distal-lateral is a combined infectious lesion of the nail, the submarginal space and the periarticular space.
In addition, in clinical practice, classification of onychomycosis by the type of pathogen is sometimes used, which is of great importance for choosing an adequate therapy scheme for the pathological process. According to this classification, dermatophytic, candidiasis and mold onychomycosis are isolated.
Symptoms and diagnosis
Visual manifestations of the disease are determined by the severity of the pathology. At the same time, there are common clinical symptoms of onychomycosis, which include the obligatory lesion of the skin of the feet and palms with a fungus with itching, cracks and peeling. The degree of damage depends on the virulence of the pathogen and sensitization of the skin. In addition, there is the appearance of white or yellow spots in the horny substance of the nail, a change in its transparency and color. There may be inflammatory phenomena in the periarticular space, the addition of a secondary infection. There is a violation of the trophism of the dermis and the horny plate of the nail, a change in the consistency, density and configuration of the nail plate, the formation of hyperkeratotic thickening, increased fragility of the nail and its ability to crumble, dystrophic manifestations, separation of the horny plate from the nail bed (onycholysis) with atrophy of the nail and the submarginal dermis.
The disease is pre-diagnosed on the basis of anamnesis and clinical manifestations. The diagnosis is confirmed by examining the affected area in the rays of a Wood lamp (luminescent diagnosis), confocal laser microscopy of scrapings from the lesion to fungi, sowing the test material on nutrient media. If an oncological process is suspected, microbiological and histological studies are carried out in the periarticular and subarticular space. Onychomycosis is differentiated with psoriasis, lichen planus, onychodystrophy, keratodermia, Darye’s disease, paronychia, eczema, photonycholysis, trauma and congenital pachionychia.
The methods of treatment are determined by the clinical type of pathology. A special program has been developed for practicing physicians – the KIOTOS index, which regulates the choice of therapy depending on the type of onychomycosis, the prevalence of the process and the degree of hyperkeratotic changes. Superficial nail damage requires only local therapy with the use of antimycotic, antibacterial and keratolytic lacquers and creams, clotrimazole and miconazole-based patches.
A deeper lesion of the nail plate with partial detachment of the nail involves the connection of systemic or combined therapy using special nail treatment, antimycotics of the azole group and allylamines inside, correction of background pathology and symptomatic therapy with drugs that improve blood microcirculation, for guaranteed transportation of the necessary therapeutic dose of antimycotic to the focus of smoldering infection.
The complete defeat of the nail by a fungal infection requires minimally invasive (with the help of a keratolytic patch) or radical removal of the horny plate in combination with the rehabilitation of the bed, postoperative antiseptic and antimycotic dressings, followed by restorative therapy with gelatin solutions and mineral and vitamin complexes. At the final stage of treatment, the use of physiotherapy is indicated: UHF, amplipulse therapy, diathermy and other techniques. The duration of the course of treatment is determined taking into account the KYOTO index. With the use of modern drugs, onychomycosis therapy is quite effective, in 10% of cases relapses are possible, requiring an individual approach to the patient.
There are primary and secondary prevention of the disease. Primary prevention involves preventing the development of onychomycosis in healthy people, secondary – eliminating the possibility of relapse. In primary prevention, priority belongs to compliance with the rules of individual hygiene, adequate regular care of the nails of the hands and feet, preventive use of external antifungal agents (varnishes, creams) when visiting swimming pools, saunas, baths, sports and gyms, timely referral to a dermatologist at the first suspicion of onychomycosis. Secondary prevention consists in a clear distinction between reinfection and relapse, which plays a crucial role in the appointment of therapy. The prognosis is relatively favorable, taking into account cosmetic defects that worsen the quality of life of patients, the duration of therapy and the possibility of relapses.