What is the diagnosis and treatment for Tinea cruris (Jock itch)?

From the Guidelines

Tinea cruris can be effectively treated with terbinafine 1% cream applied daily for 1 week, resulting in a mycological cure rate of approximately 94%. When considering treatment options for Tinea cruris, it is essential to prioritize those with the highest cure rates and fewest side effects.

• The use of terbinafine 1% cream is supported by evidence from a study published in Pediatrics in 2017 1, which highlights its effectiveness in treating Tinea cruris.
• Other treatment options, such as butenafine and clotrimazole, are also available over-the-counter, but terbinafine has been shown to have a higher cure rate.
• Oral itraconazole (100 mg daily for 2 weeks or 200 mg daily for 1 week) is also an effective treatment option for adults, but it is essential to weigh the benefits and risks of oral antifungal medications.
• To prevent recurrence, it is crucial to maintain good hygiene, keep the affected area clean and dry, and avoid sharing personal items.
• The infection is caused by dermatophyte fungi, typically Trichophyton rubrum, which thrive in warm, moist environments, making it essential to create an environment unfavorable for fungal growth.
• Treatment should be continued for at least one week after symptoms resolve to prevent recurrence.
• It is also important to note that terbinafine is approved for children 12 years and older, while butenafine is only approved for adults.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Sufficient Econazole Nitrate Cream, 1% should be applied to cover affected areas once daily in patients with tinea pedis, tinea cruris, tinea corporis, and tinea versicolor, and twice daily (morning and evening) in patients with cutaneous candidiasis however, candidal infections and tinea cruris and corporis should be treated for two weeks Uses • cures most athlete's foot (tinea pedis) • cures most jock itch (tinea cruris) and ringworm (tinea corporis)

• Treatment duration: Tinea cruris should be treated for two weeks 2.
• Treatment options: Terbinafine (TOP) cures most jock itch (tinea cruris) 3.
• Application: Econazole Nitrate Cream, 1% should be applied once daily to cover affected areas in patients with tinea cruris 2.

From the Research

Definition and Diagnosis of Tinea Cruris

• Tinea cruris, also known as jock itch, is a superficial fungal infection caused by dermatophytes 4.
• Diagnosis is usually based on history and clinical appearance, plus direct microscopy of a potassium hydroxide preparation 4.
• Culture or histologic examination is rarely required for diagnosis 4.

Treatment of Tinea Cruris

• Topical therapy is generally successful unless the infection covers an extensive area or is resistant to initial therapy 4.
• Tinea cruris infections are usually treated for two weeks 4.
• Treatment should continue for at least one week after clinical clearing of infection 4.
• Topical antifungal treatments, such as terbinafine, naftifine, and clotrimazole, are effective in treating tinea cruris 5, 6, 7.
• Allylamines, such as naftifine and terbinafine, are more convenient as they allow for a shorter duration of treatment compared to azoles 7.
• Combinations of azoles with corticosteroids may be slightly more effective than azoles alone for clinical cure, but there is no statistically significant difference with regard to mycological cure 6.

Comparison of Topical Antifungal Treatments

• A study comparing 1% butenafine and 1% clotrimazole in tinea cruris and tinea corporis found that butenafine exhibited higher clinical cure and mycological cure rates at the end of 1 week, but the difference was not statistically significant at 4 and 8 weeks of treatment 8.
• Another study found that terbinafine showed a statistically significant higher clinical cure rate compared with placebo, and naftifine showed higher mycological cure rates compared with placebo 5, 6.
• The quality of evidence for these outcomes was rated as low to very low due to imprecision, indirectness, and risk of bias 5, 6.