Chapter 140. Tinea Pedis

A 38-year-old man presents with an itchy rash on his hands and blisters on his feet for 1 week duration (Figure 140-1). Vesicular tinea pedis with bullae were present. The papules and vesicles between the fingers were typical of an autoeczematization reaction (Id reaction) (Figure 140-2). The patient was treated with an oral antifungal medication and a short burst of oral prednisone for the autosensitization reaction.

Tinea pedis is a common cutaneous infection of the feet caused by dermatophyte fungus. The clinical manifestation presents in 1 of 3 major patterns: interdigital, moccasin, and inflammatory. Concurrent fungal infection of the nails (onychomycosis) occurs frequently.

Athlete's foot

• Tinea pedis is thought to be the world's most common dermatophytosis.1
• 70% of the population will be infected with tinea pedis at some time.1
• More commonly affects males than females.1
• Prevalence increases with age and it is rare before adolescence.1

• A cutaneous fungal infection most commonly caused by Trichophyton rubrum.1
• Trichophyton mentagrophytes and Epidermophyton floccosum follow in that order.
• T. rubrum causes most tinea pedis and onychomycosis.

• Male gender.
• Use of public showers, baths or pools.2
• Household member with tinea pedis infection.2
• Certain occupations (miners, farmers, soldiers, meat factory workers, marathon runners).2
• Use of immunosuppressive drugs.

Typical Distribution and Morphology

Three types of tinea pedis

• Interdigital type—most common (Figure 140-3).
• Moccasin type (Figure 140-4 and 140-5).
• Inflammatory/vesicular type—least common (Figure 140-1).

Some authors describe an ulcerative type (Figure 140-6).