The classical presentation also occurs more often following intramuscular injections, with several medications implicated, including nonsteroidal anti-inflammatory drugs, certain antibiotics, and notably a case was reported following a patient’s self-injection of the tumor necrosis factor-α inhibitor etanercept.9,10 The delayed onset thus can present as a diagnostic dilemma, often being mistaken for a cellulitis in its initial stages, as it was in this case. This evidence concerns the gene TNF and cellulitis.