The fungus among us: Controlling athlete's foot, 'jock itch' before they spread

Key Points

National report - There is no way for athletes to avoid contracting tinea pedis, also known as athlete's foot, says Joseph Bikowski, M.D., a Sewickley, Pa., dermatologist.

"You have to understand, the fungus is every place in the environment. ... Everybody is going to be exposed; there is no 'safe zone,' he says.

"They have their first exposure to this superficial dermatophyte, and their immunologic response has been that they're able to fight it off and will no longer have problems," Dr. Bikowski tells Dermatology Times.

Dr. Bikowski, in practice for 30 years and clinical assistant professor at Ohio State University, says that later in life, however, 20 percent to 25 percent of the population may lose that ability to fight off the fungus.

"Then, not only can it recur between the fourth and fifth toes, but can involve the whole plantar surface of the foot, particularly on the plantar surface of the mid-portion of the heel.

"Even when the heel does not appear to be involved, if you scrape that asymptomatic, normal-appearing skin in the mid-portion of the heel, you can often find a positive KOH."

Toenail infection

From there, Dr. Bikowski says the infection moves to the toenail, with the great toe being the most common site to produce onychomycosis.

"Lay people will often mistakenly diagnose a thickening of the fifth toenail as fungus infection. That is not true. That's usually caused by the friction of the toe rubbing against the inside of the box toe of the shoe."

It is the toenail equivalent of a callus.

If the thickened nail occurs on the great nail, however, it is more likely to be tinea unguium.

Inguinal crease disease

From there, Dr. Bikowski says the fungal infection often can move to the inguinal crease.