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." The presence of broken skin in the inflamed area is a further warning, but there may be no obvious wound.

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.