Tinea pedis in Adult
See also in: Cellulitis DDxAlerts and Notices
Synopsis
Occlusive footwear with increased local humidity, as well as use of communal pools or baths, predisposes to tinea pedis. Athletes are at increased risk (ie, "athlete's foot"). Secondary (gram-negative) bacterial infection, especially in diabetic patients, may occur. Tinea pedis is more common in men. There is no ethnic predilection, and the prevalence increases with age.
The clinical presentation of tinea pedis may vary. The web spaces and soles are affected most frequently, but the condition may spread to involve the nonplantar surfaces of the foot as well. Interdigital maceration, especially of the lateral toe webs, is commonly seen. Tinea pedis is frequently asymmetric with one foot only being affected or disease being more widespread on one foot than the other. The degree of associated pruritus varies, but most cases are asymptomatic. Trichophyton rubrum may present with a red, scaly, moccasin-like plaque involving the sole. The bullous form of tinea pedis is usually caused by Trichophyton interdigitale (formerly T mentagrophytes var interdigitale). Onychomycosis may be associated.
Interdigital cracking and maceration may act as a portal of entry for pathogens and may predispose to lymphangitis or cellulitis. A dermatophytid reaction (also called an "id reaction") is a hypersensitivity process that can occur secondary to tinea pedis. The condition manifests on the lateral aspects of the fingers and may mimic dyshidrotic dermatitis. This hypersensitivity process will resolve with adequate treatment of the dermatophyte infection.
Immunocompromised patient considerations: In patients with human immunodeficiency virus (HIV) infection and other T-cell disorders, interdigital tinea pedis has been noted to spread to involve the dorsal foot in an extensive manner.
Codes
ICD10CM:B35.3 – Tinea pedis
SNOMEDCT:
6020002 – Tinea pedis
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Web space erythrasma is typically hyperkeratotic but can be erosive.
- Bullous tinea pedis may be confused with friction blisters or autoimmune blistering disorders.
- Maceration with mixed bacteria (mixed toe web infection)
- Candidiasis (erosion interdigitale blastomycetica)
- Contact dermatitis (irritant, allergic)
- Psoriasis – Sometimes psoriasis may be limited to soles or may present in a palmoplantar distribution.
- Palmoplantar keratoderma
- Erythema multiforme
- Dyshidrotic dermatitis (also called dyshidrotic eczema or pompholyx)
- Pityriasis rubra pilaris
- Secondary syphilis
- Keratoderma blenorrhagicum
- Pitted keratolysis – A frequently overlooked condition that causes plantar pits and malodorous feet. Its cause is bacterial, and it responds to topical antibacterials such as clindamycin solution and aluminum chloride 20% solution for drying.
- Epidermolysis bullosa simplex
- Acrokeratosis paraneoplastica
Best Tests
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Management Pearls
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Therapy
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References
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Last Reviewed:08/15/2019
Last Updated:12/09/2020
Last Updated:12/09/2020
Patient Information for Tinea pedis in Adult
Overview
Athlete's foot (tinea pedis), also known as ringworm of the foot, is a surface (superficial) fungal infection of the skin of the foot. The most common fungal disease in humans, athlete's foot, may be passed to humans by direct contact with infected people, infected animals, contaminated objects (such as towels or locker room floors), or the soil.Who’s At Risk
Athlete's foot may occur in people of all ages, of all races, and of both sexes. However, athlete's foot is more common in males than in females. Children rarely develop athlete's foot.Some conditions make athlete's foot more likely to occur:
- Living in warm, humid climates
- Using public or community pools or showers
- Wearing tight, non-ventilated footwear
- Sweating profusely
- Having diabetes or a weak immune system
Signs & Symptoms
The most common locations for athlete's foot include:- Spaces (webs) between the toes, especially between the 4th and 5th toes and between the 3rd and 4th toes
- Soles of the feet
- Tops of the feet
- On the top of the foot, athlete's foot appears as a red scaly patch or patches, ranging in size from 1 to 5 cm. The border of the affected skin may be raised, with bumps, blisters, or scabs. Often, the center of the lesion has normal-appearing skin with a ring-shaped edge, leading to the descriptive but inaccurate name ringworm. (It is inaccurate because there is no worm involved.)
- Between the toes (the interdigital spaces), athlete's foot may appear as inflamed, scaly, and soggy tissue. Splitting of the skin (fissures) may be present between or under the toes. This form of athlete's foot tends to be quite itchy.
- On the sole of the foot (the plantar surface), athlete's foot may appear as pink-to-red skin with scales ranging from mild to widespread (diffuse).
- Another type of tinea pedis infection, called bullous tinea pedis, has painful and itchy blisters on the arch (instep) and/or the ball of the foot.
- The most severe form of tinea pedis infection, called ulcerative tinea pedis, appears as painful blisters, pus-filled bumps (pustules), and shallow open sores (ulcers). These lesions are especially common between the toes but may involve the entire sole. Because of the numerous breaks in the skin, lesions commonly become infected with bacteria. Ulcerative tinea pedis occurs most frequently in people with diabetes and others with weak immune systems.
Self-Care Guidelines
If you suspect that you have athlete's foot, you might try one of the following over-the-counter antifungal creams or lotions:- Terbinafine
- Clotrimazole
- Miconazole
In addition, try to keep your feet dry, creating a condition where the fungus cannot live and grow:
- Wash your feet daily and dry them carefully, even using a hair dryer (on low setting) if possible.
- Use a separate towel for your feet, and do not share this towel with anyone else.
- Wear socks made of cotton or wool, and change them once or twice a day, or even more often if they become damp.
- Avoid shoes made of synthetic materials such as rubber or vinyl.
- Wear sandals as often as possible.
- Apply antifungal powder to your feet and inside your shoes every day.
- Wear protective footwear in locker rooms and public or community pools and showers.
When to Seek Medical Care
If the lesions do not improve after 2 weeks of applying over-the-counter antifungal creams or if they are exceptionally itchy or painful, see your doctor for an evaluation. If you have blisters, pustules, and/or ulcers on your feet, see a doctor as soon as possible.Treatments
To confirm the diagnosis of athlete's foot, your physician might scrape some surface skin material (scales) onto a glass slide and examine them under a microscope. This procedure, called a KOH (potassium hydroxide) preparation, allows the doctor to look for tell-tale signs of fungal infection.Once the diagnosis of athlete's foot has been confirmed, your physician will probably start treatment with an antifungal medication. Most infections can be treated with topical creams and lotions, including:
- Over-the-counter preparations such as terbinafine, clotrimazole, or miconazole
- Prescription-strength creams such as econazole, oxiconazole, ciclopirox, ketoconazole, sulconazole, luliconazole, naftifine, or butenafine
- Compounds containing urea, lactic acid, or salicylic acid to help dissolve the scale and allow the antifungal cream to penetrate better into the skin
- Solutions containing aluminum chloride, which reduces sweating of the foot
- Antibiotic creams to prevent or treat bacterial infections, if present
- Terbinafine
- Itraconazole
- Griseofulvin
- Fluconazole
References
Bolognia, Jean L., ed. Dermatology, pp.1174-1185. New York: Mosby, 2003.
Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed. pp.1251, 2000-2001, 2337, 2340-2041, 2446-2447. New York: McGraw-Hill, 2003.
Tinea pedis in Adult
See also in: Cellulitis DDx