Overview

What is a nail infection (paronychia)?

Paronychia is nail inflammation that may result from trauma, irritation or infection. It can affect fingernails or toenails.

Paronychia can develop when bacteria enter broken skin near the cuticle and nail fold, causing an infection. The cuticle is the skin at the base of the nail. The nail fold is where the skin and nail come together.

Healthcare providers treat paronychia with antibiotics to kill the infection. Providers may also drain pus (thick, infectious fluid that builds up around a wound). They may also culture the fluid to see what specific bacteria might be causing the infection.

Sometimes, the infection comes back or symptoms last for weeks (chronic paronychia). Chronic paronychia is more commonly caused by irritation from occupational or environmental exposures. Less often, it may be caused by a chronic bacterial or fungal infection.

How common is paronychia?

Paronychia is a common nail condition. Anyone can get a bacterial nail infection, but it’s more common among people who:

• Are exposed to irritants: Detergents and other chemicals can irritate the skin and lead to a nail bed infection. People who work with chemicals and don’t wear protective gloves have a higher risk.
• Bite their nails or cuticles: Nail biting or picking at the cuticles can create tiny cracks in the nails or cuts in the skin. Bacteria may enter the skin through these small cuts.
• Have certain skin conditions: People who have underlying skin conditions may be more likely develop nail infections.
• Work with water: Bartenders, dishwashers and other people with jobs that require their hands to be wet have a higher risk of developing paronychia.

Symptoms and Causes

What are the symptoms of a nail infection (paronychia)?

Symptoms of paronychia usually develop over several hours or days. Sometimes they take longer to develop. Symptoms appear where the nail meets the skin (the nail fold and cuticle). The sides of the nail can also be affected.

Paronychia symptoms include:

• Pain, swelling and tenderness around the nail.
• Skin that is red and warm to the touch.
• Pus that builds up under the skin. A white to yellow, pus-filled abscess may form. If an abscess forms, it may require antibiotics and/or drainage.

Untreated, the nail can start to grow abnormally and may have ridges or waves. It may look yellow or green, and it can be dry and brittle. The nail can detach from the nail bed and fall off.