Identifying Signs of Tinea Pedis: A Key to Understanding Clinical Variables

October 2015 | Volume 14 | Issue 10 | Supplement Individual Articles | 42 | Copyright © October 2015


Theresa N. Canavan MD and Boni E. Elewski MD

Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL

table 7
as tinea pedis. Erythrasma is also on the differential diagnosis for tinea pedis. Examination of the feet with a woods light can help differentiate between erythrasma and tinea pedis as Corynebacterium minutissimum fluoresces coral-red while the dermatophytes implicated in tinea pedis do not fluoresce. Non-infectious differential diagnoses include psoriasis affecting the plantar foot, as well as dyshidrotic eczema if blistering is present on the foot. Shoe contact dermatitis must also be differentiated from tinea pedis; shoe dermatitis often affects the dorsal surface of the foot, while tinea pedis primarily affects the plantar and interdigital spaces.

Clinical Evaluation and Treatment

The diagnosis of tinea pedis should be confirmed prior to initiating treatment. A scraping from the plantar surface and interdigital space should be examined microscopically with potassium hydroxide (KOH) preparation for identification of fungal elements. Fungal culture is an academic exercise and not routinely performed, as identifying the fungal species will not alter treatment decisions.
Both topical and oral agents are available. As is true for other superficial mycological infections, tinea pedis should be treated with topical antifungal medication unless the infection is extensive and treatment-resistant. Patients should also be advised to disinfect their shoes and keep their feet clean and dry, wearing fresh socks daily, as these activities will diminish the risk of re-infection and improve the chances of a cure.

CONCLUSION

Tinea pedis is a very common condition that primarily affects adults. Four presentations are possible, including interdigital type, moccasin type, vesicular type, and ulcerative type. Patients may be asymptomatic and have occult infection; so it is important for the clinician to evaluate patients’ feet for evidence of infection.
Successful treatment and eradication of tinea pedis can be challenging but is an important therapeutic goal. It is imperative to treat with topical antifungals as recommended by manufacturers since inadequately treated tinea pedis is likely to return. Chronic untreated or undertreated tinea pedis greatly increases a patient’s risk of progressing to developing onychomycosis, which can be even more difficult to cure. Patients often self-discontinue treatment when their symptoms of tinea pedis have resolved. Educating both patients and internists who treat tinea pedis on the importance of continuing treatment for the entire recommended treatment period will greatly facilitate successful treatment of tinea pedis and lessen the risk of a patient developing complications from their infection.

DISCLOSURES

Boni E. Elewski MD has received grant funding from Valeant for clinical trials; all funds have gone to the dermatology department. Theresa N. Canavan MD has no relevant conflicts to disclose.

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