P2.239: Luc’s abscess: a case of a rare complication of acute otitis media

Introduction: Acute otitis media (AOM) is a very common infection in children which can sometimes result in severe intracranial and extracranial complications. Luc’s abscess is a rare but significant extracranial complication of AOM. Despite the rarity of this complication, increasing vaccine hesitancy and antibiotic resistance may be contributing to its resurgence. This case highlights the clinical presentation, diagnosis, and management of Luc’s abscess to promote early recognition and improve outcomes.

Case Description: A previously healthy, fully immunized 4-year-old boy presented to the Emergency Department with a 3-day history of progressive left temporal swelling, fever, headache, and difficulty chewing. He denied visual changes, otorrhea, or otalgia. Two weeks prior, he completed a 10-day course of amoxicillin for a diagnosis of streptococcal pharyngitis. He was afebrile with normal vital signs. A tender, soft, non-fluctuant swelling was noted in the left temporal area without auricle protrusion (Figure 1A), and minimal discomfort to palpation of the left mastoid. The left tympanic membrane was mildly erythematous with a serous effusion present. He had a normal WBC count of 11.9 x 109/L and elevated CRP of 49.4 mg/L. A head CT scan with contrast (Figure 1B) showed a 7x3x9 mm subperiosteal fluid collection deep to the left temporalis muscle, leading to a diagnosis of Luc’s abscess. He was empirically started on broad-spectrum antibiotic coverage with cefepime and vancomycin. Pediatric ENT performed left myringotomy and tympanostomy tube placement with cortical mastoidectomy and antrotomy. Cultures from the subperiosteal fluid collection yielded Streptococcus pyogenes. He was discharged home on oral amoxicillin to complete a 4-week total course of treatment. He recovered without recurrence or complications.

Discussion: Luc’s abscess, a subperiosteal abscess which forms below the temporalis muscle, was first described as a rare complication of AOM in 1913 by Dr. Henry Luc. Clinical presentation typically involves fever and otalgia associated with temporal swelling. Few cases report associated trismus. It is hypothesized that the infection spreads to the subperiosteal area from the middle ear through the incisure of Rivinus and branches of deep auricular arteries. Head CT scan with contrast is the preferred imaging study for confirming the diagnosis. Management involves a combination of surgical debridement and 3-4 weeks of antibiotic therapy.

Conclusion: Luc’s abscess is a rare but serious extracranial complication of AOM. Due to its potential for significant morbidity, pediatricians should maintain a high index of suspicion to ensure timely diagnosis and management.