What should you know about lateral nail fold separation?

The lateral nail fold is the skin ridge along either side of the nail plate. Separation can follow repeated wet work, picking, manicures, pressure, trauma, or irritation from products. A nail infection may cause tenderness, redness, swelling, or drainage; fungal nail disease can also alter the nail and the surrounding skin. Psoriasis may produce scaling, pits, or other nail changes. The appearance alone cannot reliably identify the cause.

A clinician may examine the nail, skin folds, nearby fingers or toes, and circulation. Testing may be considered when fungus is suspected, because different causes need different treatment.

Keep the area clean and dry, wear protective gloves for prolonged contact with water or cleaning products, and avoid cutting or pushing back the fold. Do not share nail tools and pause manicures until the skin has recovered. Avoid applying leftover antibiotics, antifungals, or steroid creams without advice because the wrong product can irritate the area or obscure the diagnosis. Trim the nail carefully and protect it from catching.

Arrange prompt care for increasing redness, warmth, throbbing pain, pus, fever, red streaking, or difficulty moving the finger or toe. Seek assessment for separation that keeps returning, affects several nails, or comes with major nail colour or texture change. Severe pain, rapidly spreading swelling, or feeling unwell warrants urgent evaluation.

Ask whether the pattern fits irritation, infection, trauma, or an inflammatory nail condition; whether a sample is needed; and how long recovery should take. Discuss work, footwear, nail products, recent injury, and any skin rash elsewhere, since these details can guide the examination.