Carbuncle

A carbuncle is a contiguous collection of two or more furuncles. A carbuncle is an infection of the hair follicle(s) that extends into the surrounding skin and deep underlying subcutaneous tissue. They typically present as an erythematous, tender, inflamed, fluctuant nodule with multiple draining sinus tracts or pustules on the surface. Systemic symptoms are usually present, and regional lymphadenopathy may occur. They can arise in any hair-bearing location on the body; however, they are most common in areas with thicker skin such as the posterior neck, back, and thighs. A carbuncle can start as a folliculitis, which, if left untreated, can lead to a furuncle, and when multiple furuncles are contiguous, it becomes classified as a carbuncle. Carbuncles can be solitary or multiple.