Tinea corporis, or ringworm of the body, is a superficial fungal skin infection caused by dermatophytes. It spreads from people, pets or contaminated surfaces and is common in children and contact sport athletes.
Key symptoms
- Itchy, ring-shaped red rash that slowly grows
- One or several patches on the trunk, arms or legs
- Contact with pets, wrestlers or someone with a similar rash
- Rash that got worse after using a steroid cream
What you find on exam
- Round plaque with a raised, scaly, red border and a clearer center
- Small pustules or vesicles at the active edge
- Check the feet, nails, groin and scalp for other fungal infection
- Deep follicular bumps suggest deeper infection
Tests
- KOH preparation of scale from the border: branching hyphae
- Fungal culture if the diagnosis is unclear or treatment fails
- Skin biopsy rarely, for atypical cases
Treatment basics
- Topical azole such as clotrimazole or topical terbinafine for 2 to 4 weeks
- Continue for 1 to 2 weeks after the rash clears
- Oral terbinafine or itraconazole for extensive, deep or resistant infection
- Avoid steroid combination creams, which can hide and spread the fungus
- Keep skin dry, do not share towels and check pets
Red flags
- Widespread infection in an immunocompromised patient
- Scalp involvement or deep follicular nodules that need oral therapy
- No improvement after a full course of topical treatment
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.