• Fungal or tinea infections of the skin are common, with tinea corporis (ringworm) and tinea cruris (jock itch) affecting 10 to 20% of the general population at some point in their lifetime.
  • Tinea cruris occurs most commonly in adult men and in athletes.
  • Superficial fungal infections of the skin are caused by three dermatophytes; Trichophyton, Epidermophyton and Microsporum 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 and are spread by skin-to-skin contact with infected humans or animals (most commonly dogs, cats, guinea pigs, horses), by contact with surfaces that have been in contact with infected humans or animals, and less often by prolonged contact with dirt that harbors tinea organisms.
  • People with diabetes or who are overweight are more susceptible to tinea cruris.

For more information and photos, go to:

Skinsight.com
DermNet NZ



  • Presents as large, round, red, patches on the upper inner thigh and groin area.
    • Reddened areas can extend down inner leg toward buttocks or up toward stomach/abdomen
    • Bilateral or symmetrical due to skin-on skin contact
  • Patches have well-defined borders with central clearing 
  • Edges are bumpy or scaly
  • Burning and itching are common
  • Note: genitals are usually spared [if the patient has genital involvement, may be indicative of a yeast infection. Can treat with OTC antifungals]
  • Often co-morbid with tinea pedis (athlete's foot) and tinea unguium (aka onychomycosis or toenail infection)

Rule out the following conditions which can resemble tinea cruris:

  • Candidiasis of skin folds (candidal intertrigo) - yeast infection which may cover the genitals as well as groin area with diffuse, red, papular or pustular lesions. May also affect skin folds below the breasts, under abdomen & armpits. This may be treated with OTC antifungals.
  • Seborrheic dermatitis - appears as yellow or white, greasy, flaky 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 skinfolds in groin. Often worsens with stress. May respond to self-care treatment. More severe cases should be referred to the patient's primary care provider.
  • Psoriasis - presents as thickened, red, raised patches covered with gray or silver scales. Does not respond to antifungals. Non-contagious, often lifelong condition.  Refer to patient's primary care provider.
  • Erythrasma - often asymptomatic, bacterial infection causing slowly enlarging areas of pink or brown scaling skin in folds in the groin, armpits or between the toes. It is bilateral, irregularly shaped, and has scaly plaques. Treat with topical or systemic antibiotics.

Most patients with typical signs and symptoms of tinea cruris (jock itch) 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
    • Severely inflamed
    • Weeping or purulent
    • Painful
    • Disabling
  • Previous tinea cruris infection 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 uncontrolled or advanced diabetes, or is immunocompromised due to disease state or drug treatment.
  • Patient has symptoms of systemic illness (e.g. fever, fatigue, swollen lymph glands).
  • Unable to confirm patient's diagnosis of tinea cruris. Further evaluation is required. (See "Differential Diagnosis" above).

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.  

1Non-pharmacologic treatment for tinea cruris:

  • Skin should be kept dry to help stop infection from spreading.
  • Avoid rubbing or scratching lesions.
  • Use a hair dryer on cool setting to dry the affected area.
  • Wear loose fitting, cotton clothing or moisture absorbing synthetics.
  • Launder items used by infected person separately and often.
  • 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.
  • The main cause of tinea cruris is transfer of the microorganism from the patient's feet (tinea pedis). This can occur while changing after exercise, swimming or bathing. Instruct patient to fully dry feet and put on socks before undergarments, especially after using a public change room. Consider concomitant treatment for tinea pedis .
2. Over-the-counter drug options for treating tinea cruris:
  • OTC anti-fungal agents are 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 2cm 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 2 to 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; 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 2 to 4 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 2cm of the surrounding area. 
  • If no improvement after 1 week of topical treatment, patient should see their primry 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 are not improving
    • New lesions have appeared, or affected area is spreading
    • Pain, swelling or more redness has 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 do not usually require discontinuation.
  • If symptoms persist or are severe, possible contact dermatitis to components of cream. Advise patient to stop therapy and refer to their 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 2-4 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 2-4 weeks.

Recommend using for ONE week after symptoms resolve to prevent recurrence. Maximum duration 4 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 cruris.
    • 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 2-4 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 cruris 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 & Dr. Yvonne Shevchuk, Professor, College of Pharmacy & Nutrition
 Sponsored by the Saskatchewan College of Pharmacy Professionals
Posted May 2010. Updated May 2017