Fungal Skin Infection Treatment

Fungal Skin Infections — Types, Causes & Clinical Presentations

Superficial fungal skin infections — collectively called "tinea" or "dermatophytosis" — are among the most common skin conditions worldwide. They are caused by dermatophytes, a group of fungi that feed on keratin. These fungi invade only the outer keratin layers (skin, hair, nails) and do not penetrate living tissue in people with healthy immune systems. The three genera responsible for human infection are Trichophyton, Microsporum, and Epidermophyton.

Infections are classified by body site rather than by species, using Latin anatomical names:

• Tinea corporis (trunk and extremities)
• Tinea pedis (feet)
• Tinea cruris (groin)
• Tinea capitis (scalp)
• Tinea unguium / onychomycosis (nails)
• Tinea versicolor (a distinct condition caused by Malassezia yeast, not a true dermatophyte)

Tinea corporis — commonly called "ringworm" despite having nothing to do with worms — shows up as a ring-shaped, scaly plaque with a raised, well-defined red border and clearing in the center. It is highly recognizable via photo assessment.

Tinea pedis (athlete's foot) typically shows softened, peeling, and cracked skin between the toes. It often extends to the soles (the "moccasin" pattern) or appears as blister-like lesions on the bottom of the foot.

Tinea cruris (jock itch) shows up as a sharply defined, itchy red rash in the groin folds that typically spares the scrotum — in contrast to candidal intertrigo, which involves it.

Tinea versicolor, caused by Malassezia furfur, appears as lighter or darker patches with a fine scale, most often on the upper trunk and shoulders. It usually does not itch.

Your board-certified provider evaluates fungal skin infections via photo and video assessment. The focus is on how the lesions look, where they appear, and the clinical hallmarks of each tinea subtype. The ring shape of tinea corporis, the softened skin between the toes of tinea pedis, and the patchy spots of tinea versicolor are usually clear in high-quality photos. In most cases, this allows confident diagnosis and treatment without a KOH prep or culture.

Fungal Infections We Treat Online

Antifungal Treatments — Topical, Oral & Special Cases

For most localized tinea infections — corporis, cruris, and limited pedis — topical antifungals are the first-line treatment. Both the allylamine class (terbinafine 1% cream or spray) and the azole class (clotrimazole 1%, miconazole 2%, ketoconazole 2%) are effective. Terbinafine is generally preferred for dermatophyte infections. It kills the fungus rather than just slowing it, needs a shorter course (1–2 weeks), and has lower relapse rates than azoles.

Treatment usually runs 2–4 weeks for tinea corporis and cruris. Tinea pedis often needs 4 weeks with topical agents. To prevent relapse, keep treating for 1–2 weeks after the rash appears to clear.

Oral antifungals are appropriate in several situations:

• Extensive or widespread disease
• Immunocompromised patients
• Folliculitis-pattern tinea
• Recurrent tinea pedis despite appropriate topical treatment
• Tinea involving the nails or the scalp

Oral terbinafine 250mg daily for 2 weeks is highly effective for tinea corporis and pedis. Fluconazole 150–200mg weekly for 4–6 weeks is an alternative for tinea versicolor and suits patients who prefer weekly dosing. Tinea versicolor can also be treated with topical ketoconazole 2% shampoo (applied as a body wash, left on for 5 minutes, repeated daily for 1–2 weeks) or selenium sulfide lotion 2.5%. Patients should know that skin color may take months to even out after tinea versicolor clears, even when treatment works.

Tinea capitis — fungal infection of the scalp — is an important special case. It requires systemic antifungal therapy (oral griseofulvin or terbinafine) and cannot be treated effectively with topical antifungals alone. Tinea capitis most often affects children. It shows up as patchy scalp hair loss, scaling, and sometimes a kerion — a boggy, inflamed mass that signals severe infection. Tinea capitis needs in-person evaluation. Your provider will recognize it from your history and clinical features, then refer you to in-person care for proper management.