dermatologic disorders
Furuncles and Carbuncles
Introduction
Furuncles (boils) are skin abscesses caused by staphylococcal infection, which involve a hair follicle and surrounding tissue. Carbuncles are clusters of furuncles connected subcutaneously, causing deeper suppuration and scarring. They are smaller and more superficial than Cutaneous Abscess . Diagnosis is by appearance. Treatment is warm compresses and often oral antistaphylococcal antibiotics. (See also Overview of Bacterial Skin Infections .) Both furuncles and carbuncles may affect healthy young people but are more common among people who have obesity, are immunocompromised (including those with neutrophil defects), are older, and possibly those who have diabetes. Clustered cases may occur among those living in crowded quarters with relatively poor hygiene or among contacts of patients infected with virulent strains. Predisposing factors include bacterial colonization of skin or nares, hot and humid climates, and occlusion or abnormal follicular anatomy (eg, comedones in acne). Methicillin-resistantStaphylococcus aureus(MRSA) is a common cause. Furunclesare common on the neck, breasts, face, and buttocks. They are uncomfortable and may be painful when closely attached to underlying structures (eg, on the nose, ear, or fingers). Appearance is a nodule or pustule that discharges necrotic tissue and sanguineous pus. Carbunclesare clusters of furuncles that are subcutaneously connected. They may be accompanied by fever. 