Tinea pedis frequently causes a breakdown of the integrity of the skin’s surface. As a result, secondary infection by bacteria can develop. The host immune reaction is frequently more vigorous against bacterial infection than the fungal infection. Therefore, the fungal infection can be missed.
From a clinical standpoint, it’s best to tackle the bacterial infection by using a broad-spectrum oral antibiotic. Once the bacterial infection clears, it will be easier to identify the fungal infection. The clinician can then switch the antibiotic class, and use a broad-spectrum oral antifungal agent.
I’d recommend that the fungal infection be treated by an oral agent if possible, rather than topical agents. It’s important to completely clear up the fungal infection rather than to mask it. I’d consider topical antifungal agents as my first line only if the patient had a contraindication to the use of an oral agent.
When both infections are clear, there may be value in using a topical antifungal agent on a regular basis to prevent another fungal infection.