Mycosis of the feet

Mycosis pedis is a skin lesion caused by some dermatophyte and yeast fungi, which has a common localization and similar clinical manifestations.

[1], [2], [3], [4], [5], [6], [7]

The cause and epidemiology of foot fungal infection

Mycosis stop is one of the first places among skin diseases. The most frequent pathogens of mycosis are the red trichophyton (Trichophyton rubrum) and the interdigital trichophyton (Trichophyton mentagrophytes, var. Interdigitaie), less often this disease is caused by yeast-like fungi of the genus Candida and Epidermophyton floccosum. Infection occurs most often in baths, showers, swimming pools, sports halls with inadequate observance of sanitary and hygienic rules for their maintenance, as well as on beaches with the contact of foot skin with contaminated scales sand. Wearing impersonal shoes without first disinfecting it, using shared towels can also lead to infection. The causative agents are extremely stable in the external environment: they can grow on wood, insole shoes, long-lasting in socks, stockings, gloves, towels, as well as on items of bath equipment. Mycosis of feet usually recurs in the spring and autumn and can lead to temporary disability

Pathogenesis of mycosis of the feet

Mycosis of the foot develops in the presence of predisposing exogenous and endogenous factors that favor the introduction of the fungus. Exogenous factors include abrasions, increased sweating of feet, which is enhanced by wearing socks made from synthetic fibers, tight, not seasonally warm shoes, and leads to maceration of the stratum corneum on the feet. Endogenous causes are associated with impaired microcirculation in the lower extremities (atherosclerosis, obliterating endarteritis, varicose symptom complex, vegetative imbalance, Raynaud's symptom complex), endocrine pathology (obesity, hypercortisy, diabetes, etc.), hypovitaminosis, immunosuppression - congenital or acquired , HIV infection, the use of corticosteroids, cytostatic, antibacterial, estrogen-progestational drugs, immunosuppressants).

Symptoms of mycosis of feet

Depending on the response of the inflammatory reaction and the localization of lesions, five clinical forms of foot mycosis are distinguished: erased, intertriginous, dishydrotic, acute, squamous-hyperkeratical. Often, one patient can find their combination.

The erased form is usually manifested by weak peeling in the III-IV interdigital transitional folds of the feet and is accompanied by minor inflammatory phenomena. Sometimes a small superficial crack can be found in the depth of the affected interdigital fold. Minor exfoliation can also be expressed in the area of the soles and lateral surfaces of the feet.

Intertriginous form reminds of diaper rash. In the interdigital transitional folds of the feet, maceration of the stratum corneum occurs in the areas of friction of the contacting surfaces of the fingers, masking the hyperemia of the affected skin. It is also possible to rash bubbles. This leads to a detachment of the epidermis with the formation of erosions and cracks in the interdigital folds. Above the edges of erosions in the form of a collar, the swollen epidermis looms whitish. The defeat is accompanied by severe itching, sometimes with pain. This form of the disease can be complicated by pyogenic infection: there is swelling and redness of the skin of the fingers and rear of the foot, lymphangitis, regional adenitis. Much less often this form of mycosis is complicated by erysipelas and bullous streptoderma.

The dyshidrotic form is characterized by the precipitation of vaults and lateral surfaces of the feet of grouped vesicles on the skin. On the arch of the feet they shine through a thinner horny layer, reminiscent of their appearance and size of the rice. Vesicles occur more often on unchanged or slightly reddened skin, increase in size, merge, forming larger multi-cavity cells. When joining a secondary infection, the contents of the blisters become purulent. Rashes are accompanied by a feeling of itching and pain. After the opening of the blisters, erosions are formed with scraps of epidermis covering the edges. The disease can be accompanied by vesicular allergic rashes, mainly on the hands (mycids), reminiscent of eczematous manifestations. As the process subsides, the precipitation of fresh vesicles stops, the erosion is epithelialized, and slight peeling remains in the lesions. The dyshidrotic form of mycosis and the accompanying mycids on the palmar surface should be distinguished from the dyshidrotic eczema and allergic dermatitis, as well as from the true dyshidrosis.

The acute form of foot mycosis is highlighted by O. Podvysotskaya. This rare form of mycosis occurs as a result of a sharp exacerbation of the dysgidrotic or intertriginous varieties of the disease. A high degree of skin sensitization to fungal allergens develops most often with irrational therapy of these forms of foot mycosis. Excessive fungicidal therapy causes a sharp increase in inflammatory and exudative changes in the foci of mycosis and outbreaks. To this predispose also increased sweating of feet, their prolonged maceration and attrition. In the process, the pyococcal flora naturally complicates mycosis and causes additional sensitization. The acute form of mycosis causes predominantly the interdigital trichophyton, which has a pronounced allergic effect. The disease begins sharply with the formation of the foot on the skin, and then the shins of a large number of bubbles and vesicles on the background of edema and diffuse hyperemia. Soon there are vesicular and bullous elements on the skin of the hands and lower third of the forearms. These rashes are of a symmetrical nature. Elements of the fungus are not found in them, since they have an infectious-allergic origin. After the opening of the cavity elements, erosions are formed, surrounded by scraps of macerated horny layer. Erosions in places merge forming extensive diffusely soaking surfaces, often with purulent discharge. The disease is accompanied by an increase in body temperature, a violation of the general condition of the patient, sharp pains in the affected feet and hands. The inguinal and femoral lymph nodes increase and become painful. When making a diagnosis, it should be borne in mind that the acute form of foot mycosis resembles eczema of the feet and brushes, a bullous variety of erythema multiforme.

Squamous-hyperkeratotic form of foot mycosis is characterized by focal or diffuse thickening of the stratum corneum of the lateral and plantar surfaces of the feet. The affected areas of the skin usually have a mildly pronounced inflammatory color and are covered with small otrubrious or mucoid scales. Peeling is especially noticeable in the skin furrows, which gives the skin a powdered appearance. Some patients complain of itching in lesions. Cracks cause pain when walking. With this form of foot mycosis, which is most characteristic of the red trichophyton, mycids usually do not occur.

Diagnosis of foot fungal infection

The diagnosis is established on the basis of a characteristic clinical picture and the results of mycological examination (detection of the mycelium and obtaining a culture of the fungus).

[8], [9], [10], [11], [12]

Treatment of mycosis of the feet

External therapy with substances with fungicidal activity and a broad spectrum of action, such as azoles, allylamines, cyclopyrox and amorolfine derivatives, is recommended.