Both a furuncle and a carbuncle are skin infections caused primarily by the bacteria Staphylococcus aureus, but there are significant differences between the two. A furuncle, also known as a boil, is an infection of the hair follicle and sebaceous gland, and appears as a pus-filled red inflammation. Carbuncles are a group of furuncles and generally extend deeper into the skin. People with weakened immune systems are more likely to develop a furuncle or carbuncle, although furuncles are quite common.
Furuncles start as a small, red painful area on the skin. They may be caused by staph, other bacteria or fungi that infect a damaged hair follicle. Generally lasting about two weeks, they can develop into a large pus and dead tissue filled boil. Furuncles occur most frequently on the face, neck, armpit and buttocks. They become more painful as they enlarge.
Eventually, a white or yellow pus center develops and the furuncle may begin to ooze pus. Healing doesn’t begin until the furuncle bursts and the pus drains. A warm, damp compress can speed draining and recovery. Generally, they heal on their own, but medical intervention may be required if a furuncle lasts beyond two weeks, recurs or is accompanied by a fever. The presence of fever indicates the bacteria causing the infection may have spread to other parts of the body.
Careful hygiene practices are important to stop the spread of infection. A weeping furuncle should be meticulously cleaned and dressings disposed of sensibly. Hands and washcloths must be well washed after touching a furuncle. All clothing and bedding should be scrubbed in hot water to stop reinfection. People who have recurring furuncles have found that taking antibiotics and practicing improved hygiene help.
Without proper care, a furuncle can lead to complications. The infection can spread to other organs including the brain and to other parts of the skin. Furuncles on the face, in the nose or on the spine require medical attention. An additional complication is that furuncles can form clusters and develop into a carbuncle, a more serious condition.
A carbuncle is a group of furuncles and involves deeper layers of the skin. The mass of dead tissue, infection and pus may reach to the subcutaneous fat layer beneath the skin and could become incapable of self-draining. Carbuncles are highly contagious and easily spread to other areas of the body and other people. They can enlarge, becoming golf ball sized and very painful.
Like a furuncle, a carbuncle must drain before it can heal. Warm, moist compresses help the pus drain, and many carbuncles heal on their own. Medical attention is needed for patients with a fever or with large, deep carbuncles that don’t drain. Carbuncles located on the face or spine also require a doctor’s care. Due to their contagious nature, extreme care should be taken to stop their spread.