• Fungal or tinea infections of the skin are common. Tinea pedis (athlete’s foot) has an incidence of up to 70% of the general population.
  • More common in men and teenagers. Children under 12 years of age rarely develop the condition.
  • Superficial tineal infections of the feet are caused by three dermatophytes; Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum, which use the keratin layer of the epidermis as their source of nutrition.
  • The type of tinea infection is classified by where it is located on the body, not by the causative organism.
  • Tinea infections are contagious. Athlete's foot can be spread from person to person through contaminated towels, clothing or surfaces. Tinea dermatophytes proliferate in warm and humid places such as showers, swimming pools and changing rooms.
  • Athlete’s foot occurs most commonly between the toes and may spread to the instep or sole. The skin may be cracked or scaly with blisters, inflammation and an itching or burning sensation. It may also cover the soles of the feet and involve the toenails. This is called moccasin-type infection.
  • Tinea pedis is often the cause of tinea cruris or corporis from self-inoculation (touching affected feet to other areas of the body or scratching feet and not washing hands).
  • Risk factors for developing:
    • Direct contact with infected persons, animals, fomites
    • Conditions of increased moisture
    • Genetic susceptibility
    • Impaired immunity (diabetes, HIV, chemo)
    • Diabetes
    • Peripheral vascular disease
    • Going barefoot in public areas (e.g. change rooms)

For more information and photos, go to:

Skinsight.com
DermNet NZ

Athlete’s foot occurs most commonly between the toes and may spread to the instep or sole. May be inflamed, blistered and feel itchy, burning or painful. Often comorbid with tinea pedis & tinea unguium (onychomycosis).

Classification:

  • Interdigital infection-  the most common form
    • White, cracked or macerated areas between the toes
    • Most commonly found in the toe webs between 3rd/4th toes, or 4th/5th toes
    • Untreated interdigital infection may progress to moccasin-type tinea pedis
  • Moccasin-type infection
    • Usually present on the soles of both feet and may progress to sides and top of foot
    • Diffuse scaling and mild inflammation
    • Often affects the toenails

  • Vesiculobullous type infection
    • Blistering on the instep and middle of the bottom of the arch
    • May be inflamed, itchy or painful
    • More often seen in summer

Rule out the following conditions which can resemble tinea pedis:

  • Allergic contact dermatitis - itchy rash caused by reaction to materials in stockings or shoes (e.g. latex). Refer to Guideline for Atopic Dermatitis.
  • Candidiasis - yeast infection between the toes - moist, white peeling skin. This can be treated with OTC antifungals.
  • Seborrheic dermatitis - appears as yellow, greasy scales on scalp and may extend down to face and upper chest in the form of circular scaly pink patches. In some cases can also affect areas between the toes. May respond to self-care treatment. More severe cases should be referred to the patient's primary care provider.
  • Plantar keratosis – discrete, focused callus that typically appears in weight-bearing parts of the foot (heel or ball). Non-pharmacologic measures are the mainstay of treatment (emollients, orthotics for shoes, pumice stones).
  • Psoriasis - presents as red spots covered with thick silver scales. Refer to patient's primary care provider.
  • Erythrasma - a bacterial infection causing slowly enlarging areas of pink or brown scaling skin in folds in the groin, armpits or between the toes. Often asymptomatic. Treated with topical or systemic antibiotics. Refer to patient's primary care provider.
  • Bacterial infections which occur when there is damage to the skin such as scrapes or cuts. Refer to Guideline for Bacterial Skin Infections.

Most patients with typical signs and symptoms of tinea pedis (athlete's foot) do not require further investigation, however an assessment by the patient's primary care provider should be recommended in the following situations:

  • If the lesions are:
    • Extensive (eg. both top and bottom of feet affected).
    • Severely inflamed
    • Weeping or purulent
    • Painful
    • Disabling
  • Previous tinea pedis infection which did not fully resolve, despite appropriate treatment. Refer for evaluation and possible systemic treatment.
  • No improvement after 1 week of pharmacologic treatment. Refer for an evaluation.
  • Patient has diabetes or is immunocompromised due to disease state or drug treatment.
  • Patient has peripheral vascular disease .
  • Patient is less than 12 years of age. Children under 12 years of age rarely develop the condition. 
  • Patient has symptoms of systemic illness (e.g. fever, fatigue, swollen lymph glands).
  • Unable to confirm patient self-diagnosis of tinea pedis. Further evaluation is required. (see Differential Diagnosis above).
  • Onychomycosis (fungal nail infection) is present:
    • Untreated athlete’s foot may spread to toenails.
    • Fingernails weakened by prolonged submersion in water may become infected with tinea and also with candidal infections.
    • Extensive onychomycosis (>50% nail involvement) must be treated with oral agents that can penetrate the infection site.
    • Suspected nail fungal infection should be referred to the patient's primary care provider for diagnosis or oral anti-fungal treatment. If the patient has had a previous diagnosis and there isn't significant nail involvement, pharmacists may prescribe topical treatment for onychomycosis. 

Treatment is recommended to alleviate symptoms, reduce risk of bacterial infection and limit the spread to other areas of the body or to other individuals. 

1. Non-pharmacologic treatment for tinea pedis:

  • Skin should be kept dry to help stop infection from spreading.
  • Dry well between the toes with a clean towel everyday. 
  • Avoid rubbing or scratching lesions.
  • Use a hair dryer on cool setting to dry the affected area.
  • Wear socks made of natural, absorbent materials or synthetic blends. 
  • Wear footwear that isn't too tight & that keeps the feet cool and dry.
  • Avoid going barefoot in public places.
  • Avoid scratching affect skin to prevent spreading.
  • Launder items used by infected person separately and often.
  • Separate toes with cotton balls. 
  • Use of non-medicated powders may help absorb moisture. Do not use cornstarch or powders that contain cornstarch as these may provide nourishment for the tinea organisms.
2. Over-the-counter drug options for treating tinea pedis:
  • OTC anti-fungal agents are often available in a variety of dosage forms; creams, lotions, gels, solutions, sprays and powders. Generally, creams and lotions are most effective because they can be massaged into the affected area, increasing contact time of the medication.
  • Solutions may be easier to apply to hairy areas. Sprays and powders can be useful as adjunctive treatment, especially for oozing lesions and as preventative agents.
  • Available agents: 
    • Tolnaftate 1% available in solution, gel, powder, cream, spray
    • Clotrimazole 1% available in cream
    • Miconazole 2% available in cream, powder spray
      *azoles are generally more effective than tolnaftate
  • OTC anti-fungal treatments have been shown to be effective in treating and curing tinea infections of the skin, but they may require longer duration of treatment than with prescription agents.
  • Directions for application of creams and solutions should include:
    • Instructions to clean and dry the area first, and to apply product to visible lesions as well as 2 cm surrounding the area of visible infection. This will help treat fungus which is in the process of spreading.
    • Massage cream into area TWICE a day for 4 weeks. Products should continue to be used for 1 week after symptoms resolve to help prevent recurrent infection.
    •  
  • Pregnancy / Lactation
    • Clotrimazole and miconazole are the agents of choice in pregnancy and breastfeeding.
    • Tolnaftate has not been thoroughly studied in pregnancy and lactation.
    • In general, systemic absorption of topical antifungals through intact skin is not expected.
    • If treatment is required to a large area of skin in pregnancy, patients should be referred.

3. Prescription drug options:

Terbinafine 1% Cream and Terbinafine 1% Spray

  • Terbinafine has a broad spectrum of anti-fungal activity. It is fungicidal to dermatophytes by interfering with fungal sterol biosynthesis.
    • Directions for application of cream & spray should include:
      • Instructions to clean and dry the area first, and to apply product to visible lesions as well as 2cm surrounding the area of visible infection. This will help treat fungus which is in the process of spreading.
      • Children > 12 years old and Adults: Massage cream into area ONCE a day for 1 week only
    • Symptoms continue to improve for up to 4 weeks after treatment. [therefore, no need to apply for a longer duration]. Two weeks of treatment provided slightly better results than one week but may not be clinically significant.
    • Less than 5% is absorbed after topical application. Half-life is 14-35 hours in the stratum corneum.
    • Pregnancy: There are only limited clinical studies so current recommendations are to avoid during pregnancy. However it is not expected to increase the risk of birth defects.
    • Clotrimazole and miconazole are the agents of choice in pregnancy, but application to large areas should be avoided & patients should be referred.
    • Lactation: With topically applied cream and spray treatment, the small amounts absorbed through the skin are unlikely to affect the infant. Terbinafine should not be applied to the breast. Infants should not come into contact with any treated skin area as safety has not been established in children.
    • Pediatrics: Topical terbinafine has not been studied in children <12, so should not be recommended.

Ketoconazole 2% Cream

  • Ketoconazole is fungicidal to tinea dermatophytes by interfering with fungal sterol biosynthesis.
    • Directions for application of cream should include:
      • Instructions to clean and dry the area first, and to apply product to visible lesions as well as 2cm surrounding the area of visible infection. This will help treat fungus which is in the process of spreading.
      • Children > 12 years old and Adults: Massage cream into area ONCE to TWICE a day for 4 to 6 weeks. Products should continue to be used for 1 week after symptoms resolve to help prevent recurrent infection.
    • Treatment should meet, but not exceed recommended duration as safety for longer periods has not been established.
    • Systemic absorption is minimal to undetectable.
    • Pregnancy: Adverse effects are noted in animal studies with oral ketoconazole. Systemic absorption of topical agents is very low suggesting that ketoconazole is unlikely to have adverse effects but there is no data to confirm safety. The official recommendation is to avoid during pregnancy. 
    • Clotrimazole and miconazole are the agents of choice in pregnancy, but application to large areas should be avoided & patients should be referred.
    • Lactation: The effect on a nursing infant is unknown, but does not appear to be clinically significant. The American Academy of Pediatrics classifies ketoconazole as compatible with breastfeeding. 
    • Pediatrics: Safety and efficacy has not been established in children. Topical ketoconazole has been used without unusual adverse effect in a limited number of children. 
    •  

Steroid or combination steroid/anti-fungal products should not be recommended. The itch caused by tinea infections subsides fairly soon after topical antifungal treatment begins. Extended treatment with these products may unnecessarily expose patients to steroid side effects.

Topical nystatin is ineffective.

  • Discuss and recommend appropriate non-pharmacologic measures.
  • Improvement of symptoms such as itching and burning should occur within a few days.
  • Ensure treatment is used for the recommended duration & for 1 week after symptoms resolve. (Exception: Terbinafine- which only requires 1 week of treatment ).
  • Ensure the topical product is applied to the entire area including 
  • If no improvement after 1 week of topical treatment, patient should see their primary care provider. 
  • If symptoms worsen, contact patient's primary care provider.

Assess Benefit

  • Follow-up in 7 days to assess initial effect.
  • Refer to patient's primary care provider if:
    • Symptoms not improving
    • New lesions have appeared, or affected area is spreading
    • Pain, swelling or more redness as occurred
    • Patient has signs of systemic illness- fever, fatigue, malaise, etc.
    • Severe sensitivity to medication
  • If symptoms are improving, advise patient to continue treatment for recommended duration & for 1 week after symptoms resolve.  (Exception: Terbinafine- which only requires 1 week of treatment)

Assess Adverse Effects

  • Minor redness, itching or stinging does not usually require discontinuation.
  • If symptoms persist or are severe, possible contact dermatitis reaction to components of cream. Advise patient to stop therapy and refer to patient's primary care provider.

Detailed information on contraindications, cautions, adverse effects and interactions is available in individual drug monographs in the CPS (e-CPS), Lexi-Comp, AHFS, www.drugs.com or other reliable drug monograph references. For comprehensive drug comparisons, see RxFiles charts (www.rxfiles.ca). This information should be routinely consulted before prescribing.

OTC Products

Ingredient

Brands

Dosage / Directions

Tolnaftate 1%

Tinactin
Generics

Apply TWICE daily for 4 weeks.

Recommend using for ONE week after symptoms resolve to prevent recurrence.

Clotrimazole 1%

Canesten
Generics

Miconazole 2%

Micatin
Monistat
Generics

Prescription Products

Ingredient

Brands

DIN

Dosage / Directions

Terbinafine 1%
cream

Lamisil
cream

02031094

Adults and children >12:


Apply ONCE daily for 7 days.

Improvements persist for up to 4 weeks.

Terbinafine 1% spray

Lamisil spray

02238703

Ketoconazole 2% cream

Ketoderm

02245662

Adults and children >12:

Apply ONCE or TWICE daily for 4-6 weeks. 

Recommend using for ONE week after symptoms resolve to prevent recurrence. 

Maximum duration of 6 weeks.

  • pseudoDIN: 00951101
    • Max of 4 claims per 365 days per patient
    • All "tineas" use the same pseudoDIN and thus have a max of 4 claims per 365 days per patient altogether.

  • May prescribe sufficient quantity to treat ONE episode of tinea pedis.
    • You may prescribe an OTC product, however, they are not eligible for billing the assessment fee. 
    • Terbinafine: ONCE daily for 7 days only (long duration of action of up to 4 weeks, longer treatment not needed).
    • Ketoconazole: ONCE or TWICE daily for 4-6 weeks. Continue for an additional week after full resolution,
    • For help prescribing the proper quantity of topicals using finger-tip units, see: http://dermnetnz.org/treatments/fingertip-units.html
  • Only products with an official indication from Health Canada for tinea pedis are considered for these guidelines. Only the active ingredients in the "products" section are approved for pharmacist prescribing.
  • Drugs in Pregnancy and Lactation, 6th edition: Gerald G Briggs BPharm, Roger K Freeman MD, Sumner J Yaffe MD By Lippincott Williams & Wilkins Publishers (November 2001) Dynamed Database, Cochrane Database Syst Rev 2014 Aug 4;(8):CD009992
  • Haaf M. Use of anti-infective agents during lactation, Part 3: Antivirals, antifungals, and urinary antiseptics. Journal of human lactation 2001;17:160-6
  • Miller P. Dermatological Conditions: Fungal Skin Infections. CTMA. In: RxTx [Internet]. Canadian Pharmacists Association. Available from: http://www.e-therapeutics.ca. (In Saskatchewan available through www.shirp.ca.)
  • Mallen A. Athlete’s foot. CTMA. In: RxTx [Internet]. Canadian Pharmacists Association. Available from: http://www.e-therapeutics.ca. (In Saskatchewan available through www.shirp.ca.)
  • Stone S. Antifungal treatment chart. In: RxFiles. Available at www.rxfiles.ca by subscription. (In Saskatchewan available through www.shirp.ca.)
  • Tinea corporis. In: DynaMed. Available at https://dynamed.ebscohost.com/ by subscription. (In Saskatchewan available through www.shirp.ca.
  • Goldstein A, Goldstein B. Dermatophyte (tinea) infections. In: UpToDate. Available at www.uptodate.com by subscription.
  • Fungal skin or nail infections.In: C-Health. chealth.canoe.ca. (Free access)
  • Ringworm In: Mayo Clinic. www.mayoclinic.org. (Free access)
  • Ringworm or tinea. In Bluebook – Guidelines for the control of infectious diseases http://ideas.health.vic.gov.au/bluebook/ringworm.asp (Free access)

No part of this work may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the copyright holder. For copyright permission requests, please contact druginfo@usask.ca.

Prepared by medSask, Your Medication Information Service
Reviewed by Dr. P. Fourie, Family Physician and Dr. Yvonne Shevchuk, Professor, College of Pharmacy & Nutrition
 Sponsored by the Saskatchewan College of Pharmacy Professionals
Posted May 2010. Updated May 2017