Definition

An infection of the soft tissue around a fingernail or toenail that begins suddenly and can get worse quickly. It is usually caused when bacteria enter through a break in the skin from a hangnail or ingrown toenail, by damage to the cuticle (skin at the base of the nail), or by an injury to the area where the nail and skin meet. Acute paronychia may also sometimes be caused by treatment with certain drugs used to treat cancer or immune system disorders. Signs and symptoms include pain, tenderness, warmth, redness, and swelling around the nail. Pus may form in the skin around or under the nail. When treated, acute paronychia usually heals within 10 days.