A furuncle, also known as boil, is a skin infection involving an entire hair follicle and nearby skin tissue. Furuncles are very common and can be single or multiple. Furuncles can occur in the hair follicles anywhere on the body but they are most common on the face, neck, armpit, buttocks and thighs.
Furuncles are generally caused by staphylococcus aureus but they may be caused by other bacteria or fungi found on the skin's surface. Damage to the hair follicle allows these bacteria to enter deeper into the tissues of the follicle and the subcutaneous tissue.
A furuncle may begin as a tender, pinkish-red, swollen nodule but ultimately feel like a water-filled balloon. Pain gets worse as it fills with pus and dead tissue. Pain improves as it drains. It may drain on its own. More often the patient or someone else opens the furuncle.
The furuncle is usually pea-sized but may be as large as a golf ball. They may develop white or yellow centers (pustules) and join with another furuncle or spread to other skin areas
Some additional symptoms that may include fatigue, fever, general ill-feeling, itching before furuncle develops or skin redness or inflammation around the lesion.
A furuncle may heal on its own after an initial period of itching and mild pain. More often, they increase in discomfort as pus collects. They finally burst, drain, and then heal on their own. Furuncles usually must drain before they will heal. This most often occurs in less than 2 weeks.
Treatment by a health care provider is needed if a furuncle lasts longer than 2 weeks, returns, is located on the spine or the middle of the face, or occurs with a fever or other symptoms because the infection may spread and cause complications.
Warm moist compresses encourage furuncles to drain which speeds healing. Gently soak the area with a warm, moist cloth several times each day. Deep or large lesions may need to be drained surgically by a health care provider. Never squeeze a boil or attempt to cut it open it at home because this can spread the infection and make it worse.
Meticulous hygiene is important to prevent the spread of infection.