Final answer:
Orbital cellulitis in children is commonly a result of sinusitis, which is an infection and inflammation within the paranasal sinuses, caused by bacteria like Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
Step-by-step explanation:
In children, orbital cellulitis is commonly a consequence of sinusitis. This condition, also known as bacterial rhinosinusitis, involves infection and inflammation within the paranasal sinuses. It often occurs as a secondary infection after a viral upper respiratory tract infection. The sinuses are located near the orbit, and an infection can easily spread from the sinuses to the orbit, causing cellulitis. The most common pathogens responsible for both bacterial sinusitis and acute otitis media (AOM), include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Moreover, factors such as the anatomy of young children's eustachian tubes can facilitate the movement of fluid and bacteria from the nasopharynx, which can lead to sinusitis and consequently orbital cellulitis.