Felon

What Is It?

An infection inside the tip of the finger can form an enclosed pocket of pus (or abscess) that is very painful as it expands. A felon is a fingertip abscess deep in the palm side of the finger. It usually is caused by bacterial infection, but a herpes virus called herpetic whitlow and, more rarely, fungi also can cause felons.

Felons usually are caused by Staphylococcus aureus bacteria. It is important to receive prompt treatment for these small abscesses. If the bacteria pocket continues to expand, it can compress blood vessels in the finger and cut off the fingertip's circulation, resulting in permanent damage to the finger. Also, an untreated felon can spread its infection to the bone within the finger, creating a more serious infection (osteomyelitis) that takes much longer to cure. Like other types of infections, felons sometimes begin after the finger is punctured by a wood splinter or something else.

Symptoms

A felon causes extreme pain at the fingertip, especially when pressure is applied to the "fingerprint" surface. The end of the finger swells, is warm and turns red. There may be an accumulation of a white, thick discharge (pus). As the felon increases, the fingertip may feel numb, and bending the finger may be painful.

Diagnosis

A felon is diagnosed by physical examination. Your doctor will ask whether you have had an injury in the area. Tenderness, redness, firmness and enlargement of the fingertip are all signs of a felon. If you have small bubble-like cysts on the skin, called vesicles, and repeated episodes, it is likely the cause of herpetic whitlow.

Expected Duration

Because an enlarging abscess in the finger reduces blood supply into the area, it is hard for your body's immune system to fight this type of infection. Felons almost always need to be opened and drained by a doctor before they can heal. Most clear up within days to weeks. Healing may be faster with aggressive treatment.

Prevention

If you are going to work with wood or other materials that could cause splinters, wear protective gloves. People with diabetes who prick their fingers for home blood tests should first wash the fingertip with alcohol. Avoiding contact with others who have herpes may prevent herpetic infections, though there may be no way to know in advance who has the infection. Prompt diagnosis and treatment of a herpetic infection may prevent complications.

Treatment