Complicated postseptal cellulitis in a 7-year-old boy.

A 7-year-old boy attended the emergency department complaining of pain in the right orbital region that was accompanied by edema and symptoms of cold without fever. It was evaluated by ophthalmology that indicated empirical antibiotic treatment due to clinical suspicion of preseptal cellulitis. One week later, he returned with increased orbital edema associated with erythema and persistent pain. In addition, he reported difficulty for ocular motion and proptosis. Due to clinical suspicion of orbital abscess, an enhanced orbital CT was performed, which showed occupation of the right anterior and posterior ethmoidal cells and right maxillary sinus with air-fluid levels. In addition, a lobulated right orbital collection was visualized adjacent to the medial wall, which showed parietal enhancement and exerted mass effect on the medial rectus muscle and the eyeball, that was deformed and displaced antero-laterally. There was no evidence of optic nerve involvement or intracranial collections.These findings were reported as acute maxillo-ethmoidal sinusitis complicated with right orbital subperiosteal abscess and secondary proptosis. The abscess was confirmed and subsequently drained by nasosinusal endoscopic surgery (SENS).

Post-septal orbital cellulitis is an infectious disease that is very common in the pediatric age, and can lead to the development of several complications. The main microorganisms involved are: Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, which correspond to 95% of cases. It is a potentially serious infection due to the small amount of bone tissue that separates the periorbital tissues from the orbital and cerebral structures, as well as the nerves and vessels that perforate the thinnest part of the medial section of the orbit, the papyracea lamina. The diagnosis is based on a clinical examination that can identify fever, poor general condition, pain, edema, chemosis of the eyelids and signs of orbital disease such as proptosis, decreased visual acuity. CT is essential to stage the disease, and is the modality of choice to evaluate patients with acute sinusitis and suspected orbital involvement. We must be aware of abscess formation when there’s low-density mass effect onto the orbit, with central displacement of the mid rectus or periosteal displacement away from the etmoid lamina.

Complicated postseptal cellulitis with subperiosteal abscess is a potentially serious entity in the pediatric age that requires early diagnosis and treatment, being CT the imaging technique of choice to identify complications.

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