A Case of Orbital Cellulitis in a Seven-Year-Old Girl: The Diagnostic Significance of Intraorbital Air on Contrast-Enhanced CT

Orbital and periorbital cellulitis are common pediatric infections requiring accurate differentiation, as orbital cellulitis can lead to severe complications if left untreated. A seven-year-old girl with a history of group A β-hemolytic <i>Streptococcus</i> (GAS) infection six months earlier presented with fever and progressive periorbital swelling. Differentiation between orbital and periorbital cellulitis based on physical examination alone was challenging due to the absence of proptosis and ophthalmoplegia. Contrast-enhanced CT revealed left-sided sinusitis, fat stranding extending beyond the orbital septum, partial erosion of the lamina papyracea, and intraorbital gas, confirming orbital cellulitis. Broad-spectrum antibiotics, cefotaxime (300 mg/kg/day), clindamycin (900 mg/day), and vancomycin (1500 mg/day), were administered, leading to rapid clinical improvement. <i>Moraxella catarrhalis</i> was identified from nasal and ocular discharge cultures, and the patient fully recovered after three weeks of antibiotic therapy without surgical intervention. This case highlights the importance of contrast-enhanced CT in distinguishing orbital from periorbital cellulitis, especially in cases lacking classical orbital findings. The presence of intraorbital gas served as a key diagnostic clue, emphasizing the need for early imaging in suspected orbital cellulitis to guide appropriate management. In particular, this case demonstrates that careful assessment of symptom presentation and clinical progression can support early consideration of orbital involvement and timely decision-making regarding CT imaging.