Athlete's Foot Types and Treatments

The feet are the parts of the body that are most commonly infected by certain fungi called dermatophytes. When this happens, the result is called tinea pedis or athlete’s foot.

Athlete’s foot, from acute vesicular to chronic, is a very common problem that's experienced by up to 70% of the population at some point in life.

Who Is Most at Risk?

Athlete’s foot is common in adult males and uncommon in women. Athlete’s foot can also affect children before puberty, regardless of sex.

Athlete’s foot seems to occur most often in people who have immune systems that predispose them to infection, no matter how many precautions they take.

Types

Athlete’s foot is divided into three categories:

• Chronic interdigital athlete’s foot
• Chronic scaly athlete’s foot (moccasin-type)
• Acute vesicular athlete’s foot

Chronic Interdigital Athlete’s Foot

This is the most common type of athlete’s foot. It is characterized by scaling, maceration, and fissures most commonly in the webbed space between the fourth and fifth toes.

Tight-fitting, non-porous shoes compress the toes, creating a warm, moist environment in the webbed spaces. Many times, the infecting fungus interacts with bacteria, causing a more severe infection that extends onto the foot.

Chronic Scaly (Moccasin-Type) Athlete’s Foot

This type of athlete’s foot is caused by Trichophyton rubrum. This dermatophyte causes dry, scaling skin on the sole of the foot. The scale is very fine and silvery, and the skin underneath is usually pink and tender.

The hands may also be infected, although the usual pattern of infection is two feet and one hand, or one foot and two hands.

Acute Vesicular Athlete’s Foot

This is the least common type of athlete’s foot, caused by Trichophyton mentagrophytes. It often originates in people who have a chronic interdigital toe web infection.

Acute vesicular athlete’s foot is characterized by the sudden onset of painful blisters on the sole or top of the foot.

Another wave of blisters may follow the first and may also involve other sites of the body such as the arms, chest, or sides of the fingers. These blisters are caused by an allergic reaction to the fungus on the foot—it's called an id reaction. This type of athlete’s foot is also known as “jungle rot,” a historically disabling problem for servicemen fighting in warm, humid conditions.

Diagnosing the Infection

Athlete’s foot is diagnosed by a clinical exam. A doctor usually performs something called a KOH test. A positive KOH test confirms the diagnosis, but a negative KOH test does not mean that a person does not have athlete’s foot. Fungal elements can be difficult to isolate in interdigital and moccasin-type athlete’s foot.

Treatment

Mild cases of athlete’s foot, especially interdigital toe web infections, can be treated with topical antifungal creams or sprays such as tolnaftate or Lotrimin.

More serious infections and moccasin-type athlete’s foot should be treated with oral antifungal medications such as terbinafine or itraconazole for two to six months. All oral antifungal medications can affect the liver; therefore, blood tests should be performed monthly to evaluate liver function.