Eczema vs. ringworm: why they're confused, and why the treatment differs

Ring-shaped itchy patches, scaly skin, sleepless scratching, eczema and ringworm can look frustratingly similar, and each is regularly treated with the other's medicine.

The problem: steroid creams suppress inflammation, and also suppress the skin's defence against fungus. Put one on ringworm and the fungus flourishes into a stronger infection called tinea incognito. The reverse is unkind too: antifungals do nothing for eczema.

Some clues help at home. Ringworm often has a raised, active edge with a clearer centre, may follow a shared towel, comb or salon visit, and can affect several household members. Eczema favours the classic sites, inside elbows, behind knees, hands and face, and comes with a personal or family history of allergies.

When in doubt, come in. A two-minute skin scraping can confirm fungus on the spot. The right diagnosis is the whole ballgame.