Fungi usually make their homes in moist areas of the body where skin surfaces meet: between the toes, in the genital area, and under the breasts. Common fungal skin infections are caused by yeasts (such as Candida or Malassezia furfur) or dermatophytes, such as Epidermophyton, Microsporum, and Trichophyton. Many such fungi live only in the topmost layer of the epidermis (stratum corneum) and do not penetrate deeper. Obese people are more likely to get these infections because they have excessive skinfolds, especially if the skin within a skinfold becomes irritated and broken down (intertrigo). People with diabetes tend to be more susceptible to fungal infections as well.
Strangely, fungal infections on one part of the body can cause rashes on other parts of the body that are not infected. For example, a fungal infection on the foot may cause an itchy, bumpy rash on the fingers. These eruptions (dermatophytids, or identity or id reactions) are allergic reactions to the fungus. They do not result from touching the infected area.
Doctors may suspect a fungal infection when they see a red, irritated, or scaly rash in one of the commonly affected areas.
Fungal infections are typically treated with antifungal drugs, usually with antifungal drugs that are applied directly to the affected area (called topical drugs). Topical drugs may include creams, gels, lotions, solutions, or shampoos. Antifungal drugs may also be taken by mouth.
In addition to drugs, people may use measures to keep the affected areas dry, such as applying powders or wearing open-toed shoes.
For some infections, doctors give corticosteroids to relieve inflammation and itching.