What should you know about leg ringworm?

The rash may form a ring or an irregular patch with a more active, raised edge and clearer skin toward the centre. It can itch, scale, crack or spread outward. The name does not come from a worm; fungi cause the infection. Scratching can move the fungus to nearby skin, and shared towels, clothing or sports equipment can help it spread to other people.

A visual examination may be enough for a clinician to recognise it, although a skin sample can help when the appearance is unusual or treatment has not worked. Other rashes can resemble ringworm, so avoid assuming every circular patch has the same cause.

Keep the area clean and dry, wash hands after touching it, and use a separate towel until the rash has cleared. Wear breathable clothing and avoid scratching. A clinician or pharmacist may recommend a topical antifungal treatment for a limited skin infection; apply it exactly as directed and continue for the advised period even if the surface improves early.

Extensive, recurrent or difficult-to-treat infection may need oral antifungal treatment prescribed after an assessment. Do not use a steroid cream alone on a suspected fungal rash, because it can change the appearance and allow the infection to persist.

Arrange a dermatology review if the rash is spreading, painful, oozing, repeatedly returning, or not improving with appropriate treatment. Seek prompt care if the leg becomes rapidly red, hot and swollen, or if you feel unwell, because those features can indicate a different or additional infection.

Ask whether the appearance is consistent with ringworm, whether testing is needed, which treatment suits the location, and how long to use it. Mention recent gym, sport, household or pet exposures and any medicines or skin conditions that could affect treatment.