Ringworm on the forearm: what to know

The rash may begin as a rough, itchy patch and develop a clearer centre with a more active, raised edge. It can affect one or several areas of the forearm, and its outline may enlarge gradually. Appearance alone cannot confirm the diagnosis because eczema, contact irritation and other rashes can look similar. A clinician may inspect the border and ask about contact with infected people, pets, shared towels or sports equipment.

Keep the forearm clean and dry, wash your hands after touching it, and avoid scratching. Do not share towels, clothing or sports gear while the rash is active; wash items that touch the area. A pharmacist or clinician can advise whether a topical antifungal treatment is suitable and how long to use it. Do not apply a steroid cream alone to an undiagnosed ring-shaped rash, because it may change the appearance and allow a fungal infection to spread. Extensive or stubborn infection may need oral antifungal treatment.

Arrange a clinical assessment if the rash is spreading, keeps returning, involves several body sites, or does not improve with appropriate treatment. Seek prompt care for marked pain, warmth, pus, rapidly increasing swelling, fever, or red streaks. A weakened immune system, diabetes, pregnancy, or treatment involving several medicines also makes professional advice particularly useful.

Could this be ringworm or another forearm rash? Should the diagnosis be checked before treatment? Which product and treatment duration fit my skin and medicines? How can I reduce spread to family members or pets?