What is the most common sinus infection that leads to secondary orbital cellulitis in children?

The most common sinus infection that leads to secondary orbital cellulitis in children is associated with the ethmoid sinuses. This is primarily due to the close anatomical relationship between the ethmoid sinuses and the orbit. The ethmoid sinuses are situated between the nasal cavity and the orbit, allowing for direct spread of infection from the sinuses to the orbital tissues.

In children, infections in the ethmoid sinuses can easily ascend or spread due to their underdeveloped bony structures and the proximity of these sinuses to the eyes. Ethmoid sinusitis often presents with symptoms such as nasal congestion, discharge, and facial pain, but it can quickly escalate to orbital cellulitis, characterized by pain, swelling, and redness around the eye, as well as potential vision changes.

Other sinus infections, while they can lead to complications, are less commonly associated with orbital cellulitis in the pediatric population. The maxillary sinus can drain into the middle meatus and could also lead to complications, but the ethmoid's location plays a more critical role in the development of orbital infections.