Tinea Pedis

Key Points
Condition is a foot infection due to a dermatophyte fungus (commonly known as ringworm).
Conditon thrives in warm humid conditions and may persist for months or years in areas of where moisture occurs.
Condition may affect one or both feet, and has various patterns.
Condition most common in adult men, but there are pre-existing factors which may increase the likelihood of contraction.

Tinea pedis is a foot infection due to a dermatophyte fungus, more commonly known as ringworm. Tinea pedis thrives in warm humid conditions, and is most common in young adult men. The condition is most frequently due to trichophyton rubrum, trichophyton interdigitale, or epidermophyton floccosum.

Tinea pedis may affect one or both feet, and has various patterns. Chronic hyperkeratonic tinea refers to patchy fine dry scaling on the sole of the foot. Moccasin tinea is extensive hyperkeratonic tinea, which causes dry scaling of the sole, heel and sides of the foot (but not the top) and does not include inflammation. Athlete's foot — moist, peeling, irritable skin between the toes — is found most often in the cleft between the fourth and fifth toes. Clusters of blisters or pustules on the sides of the feet or insteps may form in some versions or round dry patches on the top of the foot.

Tinea pedis affects all ages but is more common in adults than in children. The fungus persist for months or years in bathrooms, changing rooms and swimming pools. Walking bare foot on a communal floor or sharing a towel can result in infection. Some people are particularly prone which may be because they are more exposed to the spores at home or during recreational activities, their skin produces less fatty acid (a natural antifungal agent), they wear occlusive footwear, they wear the same pair of socks or shoes for long periods, they sweat excessively (hyperhidrosis), they have some form of immune deficiency such as HIV, or they have poor circulation resulting in cold feet.

Differential Diagnosis (Other conditions with similar appearance)
Dyshidrotic Eczema
Erythema multiforme
Erythrasma
Friction Blisters
Pityriasis rubra pilaris
Psoriasis, Plaque
Psoriasis, Pustular
Syphilis

Diagnosis
Key Points
Diagnosis confirmed through clinical inspection and skin scraping cultures.
The diagnosis of Tinea pedis is confirmed through clinical inspection by microscopy and culture of skin scrapings.

Treatment
Key Points
Most forms of tinea are treated with topical antifungal creams or antifungal medications.
*If treatment is unsuccessful, consult your doctor as there may be additional causes.

Most forms of tinea are treated with topical antifungal creams or antifungal medications.

If treatment is unsuccessful consider consulting your doctor as there may be an untreated infection, reinfection from contact with spores in your surroundings or clothing, an untreated infected family member, or an alternative explanation for your symptoms such as dermatitis or psoriasis. Moccasin tinea is particularly resistant to treatment.