Fat embolism syndrome (FES) is a life-threatening complication in patients with orthopedic trauma. According to previous reports, the incidence of FES among patients who experienced orthopedic trauma varies from 0.3% to 0.9%.

　A 22-year-old man was referred to our hospital with the chief complaint of pain and a deformity in his right femur after a road traffic accident. On admission, his vital parameters were stable, but radiographic examination revealed a fracture in his right femur. Twenty hours later, he developed confusion, hypoxemia, and conjunctiva petechiae, and he was diagnosed with FES.

　The classic triad of FES includes hypoxia, neurologic abnormalities, and petechiae. FES is difficult to diagnose because of its non-specific symptoms as well as the rash that occurs in fewer than half of the cases of FES. Especially in elderly trauma patients, we tend to recognize hypoxemia and neurological abnormalities as consequences of aspiration pneumonitis and delirium, respectively. As noted in our case, it is important that clinicians must suspect the complication of FES in patients with orthopedic trauma.

　A 69-year-old man, who had past history of hives due to plaice egg, was transferred to our emergency department due to shock after first administration of 50mg of cetuximab. On admission, he had wheezing, generalized redness, and warm extremities on physical examination. Adrenaline was administered many times intramuscular injection, crystalloid and noradrenaline intravenously. After Mechanical ventilation was initiated, he hospitalized in the critical care ward. The course was uneventful, he was extubated on the 2nd hospital day, and discharged the 9th hospital day. Cetuximab-induced anaphylaxis can happen even though administration is first time owing to cross-reactivity between cetuximab and plaice egg.