Tinea pedis (athlete's foot) is a fungal infection caused by one of several types of mold-like fungi called dermatophytes. The characteristics of tinea pedis infections may vary slightly from person to person, depending on the specific dermatophyte that has caused the infection and how extensive the fungal infection has become, but most bear at least some of the same characteristics.
Common Characteristics
According to the National Institutes of Health, the most common characteristic of tinea pedis is cracked, flaking and peeling skin between the toes. The bottoms, sides or heels of the feet can also become excessively dry and cracked. Chronic infection can also lead to a thickening of the soles of the feet, along with patchy, dry scaling. These symptoms may also spread to the palms of the hands and fingers.
According to the New Zealand Dermatological Society, a common subtype called "Moccasin" tinea is characterized by dry skin on the entire sole, heel and sides of the foot, but not the top. While other types of tinea pedis can cause inflammation, this type causes no swelling of the foot.
Painful or Bothersome Characteristics
Tinea pedis can cause painful burning or stinging on the soles of the feet or between the toes. The skin on the feet may become very red, swollen or itchy (but not always). Blisters may also form on the sides of the feet or instep. When the blisters break, they can ooze and leave raw, open and extremely tender areas of skin exposed. Over time, tissue breakdown can occur, causing the skin to become soggy, eroded and painful, particularly between the toes.
Nails
Tinea pedis infections are not always limited to the skin. They may sometimes spread to the toes or fingernails. Once the fungus infects the nails, it causes them to become thick and discolored. They may also become brittle and start to crumble.
Recurrence and Secondary Infection
According to the Mayo Clinic, fungal infections such as tinea pedis create an environment that promotes recurring or secondary infections. The dermatophyte fungus can kill off some bacteria and favor the overgrowth of more resistant types of bacteria, making infections difficult to eradicate and more likely to return or spread. The NIH points out that secondary bacterial infections such as cellulitis may also develop. Cellulitis is an infection that occurs when bacteria enter the body through a break in the skin, leading to systemic (body-wide) symptoms like fever, chills, body aches and pains, and warmth, redness and inflammation at the site of the skin infection.
