Ringworm: What it looks like, how to treat it, and when to see a doctor

Ringworm has a misleading name — there's no worm involved. It's a fungal skin infection caused by dermatophytes, the same family of fungi responsible for athlete's foot and jock itch. The "ring" describes the rash itself: a circular, raised, scaly border that expands outward as the fungus spreads. According to the CDC, most ringworm infections on the skin clear up with over-the-counter antifungal treatment within 2–4 weeks.

What causes ringworm?

Ringworm (tinea corporis on the body, tinea capitis on the scalp) is caused by fungi in the genera Trichophyton, Epidermophyton, and Microsporum, according to StatPearls (NIH). These fungi live on dead skin cells, hair, and nails, and thrive in warm, moist environments. Infection spreads through direct contact with infected skin, infected animals (especially cats), or contaminated objects like towels, clothing, combs, and gym equipment. Children are especially susceptible because their immune systems are still developing and they frequently share personal items.

What does ringworm look like?

The hallmark of ringworm on the body is a ring-shaped rash with a raised, red, scaly border and a clearer center. The patch typically starts small and expands over days to weeks. It may be itchy, and the edges can develop small blisters. On the scalp, ringworm causes patchy hair loss, scaliness, and sometimes small black dots where hair has broken off at the scalp surface. In people with darker skin tones, the redness may appear darker or more subtle. A single infection can cause multiple rings, and the patches may merge if untreated.

How is ringworm treated?

For skin infections on the body, the CDC recommends OTC antifungal creams, ointments, or lotions applied to the affected area and a 1–2 inch border around it for 2–4 weeks. Effective OTC options include clotrimazole, miconazole, terbinafine, and tolnaftate. Apply twice daily and continue for the full course even after the rash disappears — stopping early allows the fungus to regrow. The CDC explicitly warns against using steroid creams or hydrocortisone on ringworm; corticosteroids suppress local immunity and allow the fungus to spread more widely, sometimes creating a severe, hard-to-treat infection called tinea incognito. Scalp ringworm is a different situation entirely — it requires prescription oral antifungal medication (typically griseofulvin or terbinafine taken for 1–3 months) because topical treatments cannot penetrate the hair follicle.

How does ringworm spread, and how can you prevent it?

Ringworm spreads through direct skin-to-skin contact with an infected person or animal, and through shared items like towels, clothing, hairbrushes, and gym equipment. NIH clinical guidance notes that the fungus can survive on surfaces for extended periods, making environmental decontamination important. To reduce spread: wash hands frequently, do not share personal items, shower promptly after contact sports or gym use, keep feet dry, wear sandals in public showers and pool areas, and wash and dry pet bedding regularly if a pet has been diagnosed. Keep the infected area covered with clothing or a bandage until treatment is well underway.

When should you see a doctor for ringworm?

See a doctor if the rash does not improve after 2–4 weeks of consistent OTC antifungal treatment, if the infection is on the scalp (which always requires prescription oral medication), if the rash covers a large area of the body or involves the face, if the skin around the rash looks infected (increased redness, warmth, swelling, pain or pus), or if you are immunocompromised. Children with scalp ringworm should see a pediatrician or dermatologist promptly, as the infection can cause permanent hair loss if untreated. Nail ringworm (tinea unguium) is also difficult to treat and almost always requires prescription medication.

How Solv can help

If your rash isn't clearing up, has spread, or you're not certain it's ringworm, a quick urgent care visit can confirm the diagnosis and get you a prescription if needed — usually without waiting days for a dermatology appointment. Find an urgent care near you and book instantly at https://www.solvhealth.com/.