Cellulitis

Cellulitis is "an acute, diffuse, and suppurative inflammation of loose connective tissue, particularly the deep subcutaneous tissues, and sometimes muscle, which is most commonly seen as a result of infection of a wound, ulcer, or other skin lesions." The condition has been known from antiquity; generations of medical students learned its signs as rubor, tumor, calor, dolor or "reddened, swollen, warm to the touch, and painful."

It is sometimes self-limiting, but almost always will need antibiotic therapy and sometimes surgical debridement and drainage. Differential diagnosis to rule out life-threatening conditions, such as deep venous thrombosis and gangrene, is essential; a presentation of the common signs of cellulitis needs urgent, if not emergent, evaluation.