What symptom is exclusive to orbital cellulitis in a child with eyelid swelling after an insect bite?

In the context of orbital cellulitis, proptosis is a key symptom that differentiates it from other conditions, such as preseptal cellulitis. While all of these symptoms can occur in various conjunctival or orbital infections, proptosis is particularly indicative of orbital involvement.

Orbital cellulitis typically arises from a primary infection or trauma, such as an insect bite, leading to inflammation that affects the tissues surrounding the eye and can potentially spread into the orbit itself. This condition often results in the forward displacement of the eye (proptosis), which is a hallmark sign of orbital involvement and reflects increased pressure or volume within the orbit.

In contrast, while vision impairment, diplopia (double vision), and pain with palpation can also be present in patients with orbital cellulitis, they are not exclusive to this condition. Vision impairment may arise due to several causes in ocular conditions, and diplopia can occur in multiple ocular pathologies due to muscle involvement. Pain with palpation may be noted in any condition affecting the eye but does not specifically elevate the concern for orbital cellulitis over other types of infections.

Thus, proptosis stands out as a unique clinical feature that, when observed alongside eyelid swelling after an insect bite, raises immediate