BACKGROUND Anti-TNF-alpha therapies were the first class of biologics to be used in treatment of moderate to severe IBD. Immunosuppression status that develops from using anti-TNF-a therapies increases the risk of serious and opportunistic infections. We present here a rare case of serious infection that developed in an IBD patient while on anti-TNF therapy. CASE REPORT Our patient was a 14-year-old boy with a history of chronic sinusitis and ulcerative colitis who had been on infliximab therapy for the last 3 years. He presented with facial swelling and worsening constant frontal headache. Imaging showed frontal scalp subgaleal abscess, mild frontal calvarial early osteomyelitis, bilateral preseptal cellulitis, and acute and chronic paranasal sinus disease. He was treated with intravenous antibiotics and underwent sinus surgery with incision and drainage of the forehead abscess. He recovered well and resumed his infliximab infusions 3 weeks after the surgery. CONCLUSIONS PPT is a serious complication of untreated sinusitis. IBD patients on biologics can have higher risk of developing such complications because of their decreased ability to fight infections. Although the risk of serious infections declines significantly after the first year of using biologics, physicians should keep a low threshold for investigating symptomatic patients for serious infections, as they require prompt intervention. Despite the potential complications from using biologics, the benefits of this therapy in IBD patients outweigh the risks.