What does tinea cruris look like and how is it treated?

Tinea Cruris: Clinical Appearance and Treatment

Tinea cruris is effectively treated with topical terbinafine 1% cream applied daily for 1 week, which achieves a mycological cure rate of approximately 94% in most cases. 1

Clinical Appearance

Tinea cruris (jock itch) presents with the following characteristic features:

• Well-demarcated, erythematous, scaly patches or plaques in the groin area
• Often with raised, advancing borders and central clearing creating a ring-like appearance
• Typically affects the inner thighs, crural folds, and can extend to the buttocks
• Pruritus is a common symptom
• More common in men than women
• Often asymmetric or unilateral initially, but can become bilateral

Diagnostic Confirmation

Before initiating treatment, confirm the diagnosis with:

• Skin scrapings from the active border of the lesion
• KOH preparation to visualize fungal elements (hyphae)
• Consider fungal culture in atypical or resistant cases

Treatment Algorithm

First-Line Treatment (Localized Disease)

• Topical terbinafine 1% cream applied daily for 1 week 1
  • High efficacy with convenient once-daily dosing
  • Approved for children 12 years and older

Alternative Topical Options

• Butenafine cream applied twice daily for 2 weeks (adults only) 1
• Clotrimazole cream applied twice weekly for 4 weeks 1, 2
• Other azole antifungals (miconazole, ketoconazole) applied twice daily for 2-4 weeks 2

Systemic Treatment (For Extensive or Resistant Cases)

• Oral itraconazole 100 mg daily for 2 weeks or 200 mg daily for 1 week 1
• Oral terbinafine 250 mg daily for 1-2 weeks 3
• Oral griseofulvin is indicated for tinea cruris caused by specific dermatophytes when topical therapy is inadequate 4

Prevention Strategies

To prevent recurrence and spread:

• Complete drying of the crural folds after bathing 1
• Use separate clean towels for drying the groin and other body parts 1
• Cover active tinea pedis lesions with socks before wearing underwear (as tinea pedis often leads to tinea cruris) 1
• Wear loose-fitting cotton underwear
• Change clothing, especially underwear and athletic wear, daily
• Avoid sharing personal items like towels or clothing 5

Treatment Pitfalls and Considerations

• Misdiagnosis: Tinea cruris can mimic other conditions like eczema, psoriasis, or candidiasis. Confirm diagnosis with KOH preparation or culture before treatment 3
• Steroid use: Avoid topical steroids alone as they can worsen the infection and lead to tinea incognito or tinea indecisiva with atypical presentations 6
• Predisposing factors: Address underlying conditions like obesity, diabetes, and hyperhidrosis that increase risk 7
• Treatment failure: Consider non-dermatophyte causes (like Candida) if standard treatment fails 1
• Follow-up: Treatment success should be based on mycological cure, not just clinical improvement 1

Special Populations

• Children: Tinea cruris is less common but can occur, especially in adolescent athletes. Topical agents are first-line; oral medications may be needed for extensive disease 7
• Immunocompromised patients: May require longer treatment courses and oral therapy even for limited disease 3
• Recurrent cases: Consider prophylactic therapy and more aggressive management of predisposing factors 8

By following this treatment approach and preventive measures, most cases of tinea cruris can be effectively managed with complete resolution of symptoms and prevention of recurrence.