A round red patch on an arm or tummy that slowly grows over several days is easy to mistake for eczema or a bug bite. This look is typical of ringworm (tinea corporis), a fungal skin infection. Despite the name, no worm is involved, and the cause is a fungus living in the top layer of skin.

Why It Happens

Ringworm fungi grow on dead skin cells. They can spread through skin-to-skin contact with an infected person, contact with pets such as dogs and cats, and shared items like towels, combs, or gym mats. Warm, damp skin tends to favor their growth.

What It Looks Like

A typical patch is pink or red and round, with a slightly raised, scaly border and skin in the middle that looks clearer, giving a ring shape. Itching is common but not always present. A child may have one patch or several, and patches can merge into irregular shapes. Ringworm on the scalp can cause scaling and hair loss and is generally treated with medicine taken by mouth, unlike ringworm on the body.

Care at Home

  • Wash and fully dry the area before applying an over-the-counter antifungal cream
  • Spread the cream a bit beyond the edge of the patch, as the package or pharmacist directs
  • Keep using it for the length of time advised, often 2-4 weeks, even when it looks better
  • Use separate towels, combs, and bedding, and wash them often
  • Have pets checked by a veterinarian if they have patchy hair loss or scratching
  • Wash hands after touching the rash Doctors generally advise against covering the rash with a tight bandage.

Common Misunderstandings

The most common mistake is treating the patch as eczema with hydrocortisone or other steroid cream. Steroids can calm redness at first but may let the fungus grow and change how the rash looks, making it harder to diagnose. Long-term use of combination steroid-antifungal creams also deserves caution. Another myth is that ringworm means a child is unclean; clean, healthy children catch it through ordinary contact.

When to Consider Talking with a Pediatrician

See a pediatrician if there is no improvement after 1-2 weeks of antifungal cream, if patches are widespread, or if the rash is on the scalp, face, or nails. The doctor may scrape a few scales to check for fungus under a microscope. Ask about the right time to return to daycare or school once treatment has started.

Seek emergency care or urgent care right away if the area becomes quickly swollen, very painful, or starts oozing pus, if redness spreads fast with fever, or if the face swells and breathing looks difficult. This information is based on U.S. (CDC/AAP) guidance; if you live elsewhere, check with a local pediatrician for country-specific recommendations. This information isn’t a diagnostic tool and doesn’t replace advice from a medical professional.