Tinea Infections: Key Points for Practice

Lilian White, MD
December 8, 2025

An AFP article recently reviewed updates in the diagnosis and management of tinea infections. Tinea infections are the most common superficial fungal infection, affecting 25% of the world’s population. In adults, onychomycosis is the most common presentation. In children, tinea capitis is the most common tinea infection. An emerging dermatophyte strain (Trichophyton mentagrophytes genotype VII) causes infection in areas of sexual contact, particularly in men who have sex with men.

Clinically, the signs most consistent with a tinea infection include maceration, concentric rings, central clearing, and overall clinical impression (positive likelihood ratios of 1.7, 1.4, 1.2, and 1.5, respectively). Photos of typical tinea infections can be found in the AFP article.

Based on expert consensus, in-office diagnostic testing for tinea infections is generally recommended if feasible (with exception of suspected onychomycosis, tinea capitis, and kerion—when diagnostic testing is more strongly recommended because oral therapy is required). Options for diagnostic testing include direct microscopy (e.g., KOH preparation), histology, molecular methods (eg, polymerase chain reaction [PCR]), and culture. Fungal culture is only about 60% sensitive but has a high specificity (along with histology and PCR), approaching 100%. PCR testing is increasingly used for diagnosis with a negative predictive value of 95%. Histology and PCR testing have the highest sensitivity at 85% to 88%.

When diagnostic testing for tinea is not possible or is impractical for tinea infections, an empiric course of treatment with 2 weeks of topical antifungal therapy alone may be considered. This course is generally recommended to avoid antifungal and corticosteroid combinations, which can contribute to antifungal resistance and result in skin atrophy or systemic adverse effects. Diagnostic confirmation should precede treatment of onychomycosis and tinea capitis; however, empiric treatment of kerion is indicated while awaiting diagnostic test results.

While terbinafine resistance is increasing worldwide, topical antifungal therapy remains the preferred treatment for tinea infections, including onychomycosis, because of its effectiveness, tolerability, and low cost. Topical clotrimazole and miconazole are generally no longer recommended because of lack of effectiveness. Oral ketoconazole is generally avoided because of risk of hepatotoxicity.

Recently, a large meta-analysis reported that terbinafine is more effective than azoles for mycologic cure of onychomycosis. The course of treatment is 6 to 12 weeks, but it takes 9 to 12 months to assess for cure because of the slow growth of toenails. Oral itraconazole may be used as a second-line option in patients who do not achieve cure with terbinafine.

For the treatment of tinea capitis, oral agents alone or prescribed with concurrent topical treatments (ie, antifungal shampoos such as ketoconazole or selenium sulfide) are options. Empiric treatment with antifungal shampoos may be considered for asymptomatic members of the patient’s household, but testing is not recommended.