Pseudomonas aeruginosa retro-orbital abscess and cerebritis leading to a diagnosis of interleukin-1 receptor-associated kinase-4 deficiency.

Invasive ocular infections due to Pseudomonas aeruginosa infections are rare. Previous studies have reported cases in immunocompromised hosts, patients after surgery (radial keratotomy), aswell as in neonates.Herein,wepresent the case of a healthy male infant who at 9 months of age presented to the emergency department with a right upper eyelid preseptal cellulitis. He neither had a history of eye trauma nor abnormal family history. On Day 3 after admission, he had worsening inflammation, prompting us to examine him under anesthesia. The results of the examination revealed a marked area of necrosis affecting the right upper eyelid margin. The necrosis was later excised by making a linear crease incision above the upper eyelid lid margin. P. aeruginosa was isolated from the eye swab used. The identity and antibiotic susceptibility of the bacterium were determined using VITEK 2 system (bioMérieux), which showed the isolate to be sensitive to piperacillinetazobactam, ciprofloxacin, gentamicin, and meropenem. Antibiotic treatment was changed to piperacillin-tazobactam, which was administered for 5 days after which the child was discharged home, with 5 days of ofloxacin eyedrops recommended. Two weeks later the child was re-admitted with recrudescent preseptal cellulitis and was treated with intravenous flucloxacillin and gentamicin. On Day 6, he developed cough, and influenza A infection was diagnosed. On Day 11, the child rapidly developed orbital cellulitis with a mild proptosis. A computed tomography scan of the orbits showed a right subperiosteal collection adjacent to the olfactory plate, which was surgically drained. On Day 14, he became obtunded. Magnetic resonance imaging scan of the