It continues to surprise me how many people don’t realize that they have athlete’s foot. This common fungal infection, known as tinea pedis, is frequently mistaken simply as “dry skin.” The name “athlete’s foot” is a misnomer as the problem is not limited to athletes. It is reported to affect between 30% to 70% of the population. There are a variety of responsible fungi, but trichophyton rubrum is the most common. These fungi are common in the environment and grow in the dead “keratinized” layer of the skin, known as the stratum corneum. Genetics, climate and occlusive footwear predispose individuals to tinea pedis and it is much more common in adults than children.
Signs of Athlete’s Foot
Tinea pedis is frequently asymptomatic but the signs may include dry, scaly skin with or without tiny bubbles around the sides and along the bottom of the feet. The skin between the toes may have a white, pasty appearance and often there is an accompanying toenail fungus. Other common or more serious conditions such as psoriasis, eczema, allergic skin reactions, cellulitis and callused skin could be confused with tinea pedis. A physician should be consulted if there is any redness, swelling, bleeding, inflammation, pain or if there are open sores or other complicating factors such as diabetes, vascular insufficiency, advanced age, cancer or immunosuppression.
There are many effective antifungal topical products available for treating tinea pedis. In recent years, prescription antifungal creams have undergone substantial price increases, but economical and excellent over the counter products are available such as generic terbinafine cream or butenafine cream (Lotrimin Ultra). I do not recommend antifungal powders or sprays. For maximum benefit, it is just as important to use the medicine properly as it is to choose the right medicine. Apply the cream to both feet in a thin layer from the ankle down covering the entire foot surface. It should be applied every morning after showering for two to four weeks. Recurrences are likely, so be prepared to start treatment early for any signs of flare-ups. While all medications may have the potential for adverse reactions, problems with over the counter topical antifungal medications are unusual. The most likely problem would be an allergic rash, in which case the medication should be stopped immediately. If your problem is not improving within two weeks (or certainly if it is worsening), see your physician for evaluation.
In addition to using a topical antifungal cream in the mornings, applying a “keratolytic” exfoliating cream or lotion at bedtime will increase the effectiveness of the antifungal cream. These products work by helping to remove the dead keratinized layer of skin inhabited by the fungus. They also by allowing better penetration of the antifungal cream. Keratolytic products contain various concentrations of urea (10%-20%), salicylic acid (3%), or alpha hydroxy acids (12%). They may be used indefinitely to keep the feet smoother, softer and to prevent recurrences. A warning, keratolytics should not be applied to sensitive, irritated, inflamed or open skin.