Carbuncle and furuncle: what to know

The skin may become tender, swollen, warm, and red around a pus-filled lump. A furuncle begins around one follicle; several nearby infections can join beneath the skin to form a carbuncle. Drainage may appear through more than one opening. Friction, shaving, sweating, or bacteria entering a small break in the skin can contribute, but the appearance alone cannot identify the cause.

Use a clean warm, moist cloth for short periods to ease discomfort and encourage natural drainage. Keep the area covered with a fresh dressing if it leaks, wash your hands after touching it, and avoid sharing towels, razors, or clothing. Do not squeeze, pierce, or cut the lump. A clinician may recommend antibiotics or a procedure to release trapped pus; see Antibiotics For Skin Infection or Abscess Drainage for treatment information.

Arrange prompt medical review if the swelling is enlarging, very painful, repeatedly returning, or surrounded by spreading redness. Seek urgent help for fever, chills, marked weakness, red streaks, or swelling near the eye. Assessment is also sensible when you have diabetes, reduced immunity, or difficulty healing, because an infection may need closer follow-up.

Ask whether this is a furuncle, carbuncle, or another type of abscess; whether drainage is appropriate; how to dress the area; and which symptoms should trigger an urgent return.