What can happen if ringworm is left untreated?

Ringworm can gradually enlarge at the edge while the centre changes, and scratching may break the skin. Ongoing inflammation can make the area sore, crusted or vulnerable to a secondary bacterial infection. On the scalp, infection can cause broken hairs and patchy hair loss; on the nails, it can thicken and distort the nail. Not every itchy or scaly patch is ringworm, so a persistent rash needs confirmation rather than repeated trial treatments. See [Ringworm](/conditions/ringworm/) for broader context.

Book a medical or pharmacy assessment if the rash is spreading, recurrent or uncertain. Keep affected skin clean and dry, avoid scratching, and do not share towels, clothing, combs or sports equipment. Wash hands after touching the area and launder items that contact it. A limited skin infection may be treated with a topical antifungal, while scalp, nail or extensive disease may need prescribed oral treatment. Do not stop a recommended course simply because the visible edge looks quieter. Explore [Topical Antifungal Treatment](/treatments/medical-dermatology/topical-antifungal-therapy/) and [Oral Antifungal Treatment](/treatments/medical-dermatology/oral-antifungal-therapy/).

Seek prompt care for fever, pus, rapidly increasing redness, severe pain, marked swelling, facial involvement, or a scalp area with tender swelling and hair loss. Arrange an earlier review for a young child, pregnancy, diabetes, immune suppression, or treatment that is not helping. These situations can change which examination and medicine are appropriate.

How can we confirm the rash is ringworm? Which body sites should I check for spread? Do I need topical or oral treatment? How can I reduce transmission at home, and when should the area be reassessed?