Fungal Infection of the Feet

Fungal infections are caused mainly by anthropophilic dermatophytes, i.e. fungi that are transmitted from person to person by direct contact or through objects (shoes, socks, floors, etc.). The most common dermatophytes that cause fungal infections on the feet are trichophyton rubrum and trichophyton interdigitale. Fungal infections of the feet are developed in conditions of high humidity and increased temperature. For example, when we wear tight shoes from synthetic material for too long. Also, in people with very narrow interphalangeal spaces, or in athletes whose feet sweat a lot, the condition is very common.

There are three clinical types of fungal infection:

The most common is the type that affects the interdigital spaces, usually between the 4th and 5th finger and is manifested by itching, cracks in the skin and pain, while a whitish color of peeling skin is observed.

It can also be extended to the skin under the toes, while it may improve (in early types) when open shoes are used. The problem is the relapses which are treated with local preventive measures such as the good drying of the feet after the bath so that the moisture does not remain frequent changes of socks as well as the use of a powder that absorbs perspiration.

Another type of fungal infections on the feet causes peeling and redness on the underside of the toes and soles. In this type the skin appears dry, scaly or even cracked and is called foot hyperkeratosis.

Finally, there is a form of mycosis that looks like eczema and initially appears as blisters with intense itching that gradually dry up while new ones appear. This type of fungus is common in the summer and is mainly found in the arch of the foot.

Fungal infections of the feet can cause strong smelly feet (bromodosis). In the beginning of fungal infection of the feet, it is required only a local treatment with antiseptic soaps and topical antifungal creams or gels or powders on a daily basis. The main antifungal substances for local treatment are imidazole derivatives, amorolfine and allelamines. Wearing open shoes and the good drying from moisture also helps.

In more advanced or extensive cases, oral treatment with antifungal agents is required in addition to local treatment. There are 3 classes of systemic antifungal drugs: triazoles, allelamines and griseofulvin. Systemic treatment must be administered with caution and possible interactions with other medications that the patient may be taking must be taken into account. As some of the antifungals can cause hepatotoxicity they should not be given to patients with impaired liver function.