What should you know about nail ringworm?

Nail ringworm is commonly called fungal nail infection; it is not the same as a ring-shaped rash. The nail may become yellow, white, or brown, thickened, brittle, crumbly, or separated from the bed. Fungal infection can affect one or more nails and may occur with scaling or a rash on nearby skin. Because psoriasis, trauma, and other disorders can look similar, a clinician may take a nail sample before prescribing treatment. Read about [Ringworm](/conditions/ringworm/), [Skin Rash](/symptoms/skin-rash/), and [Scaly Skin](/symptoms/skin-scaling/).

Keep the nail short and dry, change damp socks or gloves, and avoid sharing nail tools, towels, or footwear. Do not tear off the nail or rely on a skin cream to treat a thick nail without advice. A limited infection may be treated with [Topical Antifungal Treatment](/treatments/medical-dermatology/topical-antifungal-therapy/); infection involving deeper or broader nail areas may need [Oral Antifungal Treatment](/treatments/medical-dermatology/oral-antifungal-therapy/). Medication choice depends on the organism, other medicines, and your health.

Arrange assessment for a persistent thick, crumbly, or discoloured nail, especially if it is spreading to other nails or accompanied by athlete’s-foot symptoms. Seek prompt care for increasing pain, warmth, swelling, pus, fever, or rapidly worsening redness. People with diabetes, poor circulation, or reduced immunity should seek advice early when a foot or finger becomes damaged or infected.

Could this be fungus, psoriasis, or trauma? Should a sample confirm the diagnosis? Would a topical or oral medicine suit the affected nail? Are there interactions or monitoring needs with the proposed medicine? How can I reduce reinfection from skin, footwear, or shared tools?