Fungal infections of the skin

Proven content

Fungal infections are not as common as infections caused by bacteria or viruses. With approx. 250 thousand described species of fungi, only about 200 species can cause disease in humans, and only a few fungi are capable of causing serious disease in healthy people. Most infections occur in people who have a weakened immune system.

In most cases, fungal infections are exogenous, i.e. their source is in the external environment. On the other hand, endogenous fungal infections are the result of an infection with fungi that are part of our flora and are mainly caused by yeast-like fungi of the genus Candida.

Mycoses of the skin belong to the group of superficial mycoses in which the infection is limited to the outer layers of the skin, hair, nails and mucous membranes. Most infections are mild and, with proper diagnosis and treatment, no complications occur. The classic division of mycoses of the skin includes:

Dermatophytozy

This term is used to describe skin, hair or nail infections caused by filamentous fungi dermatofitami. These fungi can only cause superficial infections, because they need keratin for their life.

Infections with dermatophytes are typical exogenous infections. The source of the fungi can be humans, animals or the external environment (soil, rotten wood, etc.)

In order for an infection with dermatophytes to occur, you must have the proverbial bad luck, i.e. factors such as: weakened immunity, tendency to crack the skin (especially of the feet), failure to follow the basic rules of using public baths or showers, excessive sweating, using shoes or hats of unknown origin (second-hand clothing stores), atypical skin diseases, few pets with ringworm.

Dermatophyte infections can take the form of:

— smooth skin mycosis = most commonly seen in children where pets are the main source of infection. The following picture is characteristic: a round or oval lesion, sharply limited from the healthy skin, with a characteristic peeling in the middle and accompanied by itching; lesions can be single or multiple and are most often located around the neck, cleavage, face or the dorsal surfaces of the hands

— mycosis of the feet and hands = mycosis concerns the interdigital spaces, hands or soles and mycosis is very often observed in soldiers and sportsmen; infection is very common as a result of contact with wooden grilles in saunas, public bathrooms or swimming pools. The clinical picture depends on the place where the infection develops and the most common is the characteristic cracking of the skin between the fingers accompanied by itching, peeling and inflammatory changes.

— inguinal mycosis = erythematous-scaly lesions are limited to the groin area and this type of mycosis most often occurs in men. Infection is most often spread through direct contact or through items such as: sponges, towels, etc. the contributing factors include: excessive sweating, diabetes, obesity, wearing elastic underwear or tight pants

— onychomycosis = this type of infection is mainly seen in adults; very rarely seen in children. The mycosis most often begins with the toe nail, and then gradually progresses to the nails of other toes. Onychomycosis affects the feet more than the hands. The nail attacked by the fungus becomes thickened, discolored (pale yellow spots), cracks, peels, and finally completely destructs. Infection begins from the free edge of the nail or from the side of the shafts

— mycosis of the scalp = mostly children and self-healing after adolescence; in most forms of mycoses of the hair, there is no permanent alopecia or scarring, and after healing, the hair regrows completely; Hair mycosis can be suspected if there are foci of exfoliation on the scalp with broken hair

Candidiasis

Fungi caused by fungi of the genus Candida, most often by the species Candida albicans. These fungi are very often found in the flora of the oral cavity and the gastrointestinal tract, and infections are most often observed in people with a significant decrease in immunity. They are very often the first sign of HIV infection.

The factors contributing to candidiasis include: congenital and acquired immunity disorders, chronic antibiotic therapy, immunosuppression, chemotherapy and radiotherapy, steroid therapy, diabetes, pregnancy, oral contraception, microtrauma, skin maceration, poor hygiene.

Superficial candidiasis can take the form of:

— skin candidiasis = changes are intertriginous and most often located in the area of ​​skin folds (in the groin, in the buttock gap, under the breast or in the interdigital spaces). The changes are erythematous-exudative and exfoliating, most intense in the depth of the fold, while papular and vesicular eruptions are observed on the periphery.

A characteristic type of skin candidiasis is the so-called diaper thrush observed in hygienically neglected infants.

— mucosal candidiasis = may affect the mouth, vulva and vagina or the glans and foreskin; in the acute form, whitish raids closely adhering to the mucous membranes are observed, accompanied by a burning sensation and itching

— candidiasis of the mucous membranes = mycosis affects the corners of the mouth and is usually manifested by painful cracking and erosions on both sides

— candidiasis of periungual shafts and nails = infection begins with the nail fold and affects fingernails; redness and swelling of the nail fold are characteristic, from under which the serous-purulent content comes out; as a consequence, as a result of the chronic duration of the process, the nail plate is damaged

Diagnosis of mycoses

The clinical picture for individual types of mycoses of the skin is not characteristic, therefore it is very important to perform a mycological examination that will allow to identify the species of the fungus. Additionally, the sensitivity of fungi to antifungal drugs can be determined, which is especially important in the case of mycoses caused by fungi of the genus Candida.

The best way to collect the material is to collect it directly in the mycological laboratory by a qualified person and consists in exfoliating the epidermis or cutting the nail at the periphery of the fungal lesion. In the case of diagnosing dermatophyte infections, the waiting time for the result may be up to 5-6 weeks.

Therapy of fungal infections

The basic treatment of mycoses comes down to the use of an appropriate antifungal drug.

In most cases, it is enough to use local treatment in the form of ointments, creams, vaginal pessaries or varnishes. Oral treatment is used in the case of extensive fungal lesions of the skin, hair mycosis, chronic mycoses or mixed infections (e.g. feet and nails).

Antifungal drugs in the form of varnishes are used in the case of onychomycosis.

The duration of treatment varies and depends on the form of mycosis. In most cases, topical treatment is carried out twice a day until the symptoms disappear and also prophylactically for 2 weeks.

In some cases, oral treatment may last up to 12 weeks (onychomycosis) or a month (tinea pedis).

Prophylaxis of mycoses

In order to reduce the risk of mycosis, it is very important to reduce the favorable factors, such as: treatment of disposable diseases, e.g. diabetes, hormonal disorders, compliance with the correct rules of using public showers or saunas, the use of probiotic preparations after antibiotic treatment, proper nutrition, compliance with hygiene rules ( systematic cutting of nails; drying feet, etc.). It is also important to combat fungi in the environment by treating sick animals, cooking and ironing linen, getting rid of contaminated shoes or previously used manicure tools.

Text: Mirosław Jawień, MD, PhD

Also read: Purulent skin infections