Paronychia is most commonly caused by a staph infection, although other bacteria can cause infection. Bacteria can enter the skin through cuts and hangnails, ingrown nails, or trauma to the nail bed like accidents or nail biting. There are two types of paronychia. Acute paronychia can appear rapidly and only impacts the skin around the nail. Chronic paronychia develops gradually and can affect multiple nails.
Symptoms usually develop where the nail meets the skin. Pain, swelling, and redness are all common. A pus-filled abscess may also form. Over time, the nail can start growing abnormally, develop ridges, look yellow or green, become brittle, and detach from the nailbed.
Physicians will typically diagnose paronychia with a physical exam. Tests are usually not required, although a sample of tissue may be sent to a lab to test for bacteria or fungi. In severe cases, x-rays may be required to determine conditions in the underlying bone.
Most acute cases can be treated with oral antibiotics and by soaking the nail in warm water. If pus has built up around the nail and is not draining on its own, it must be drained by a physician. Part or all of the nail may need to be removed if the infection progresses. Chronic infections are often treated with topical and oral antibiotics, and antifungal or steroid medications. In severe cases, a portion of the nail fold may need to be surgically removed to eliminate the infection. Paronychia can be prevented by avoiding manicures, nail biting, and prolonged exposure to water.