Peri-orbital cellulitis often presents with gradual onset unilateral eyelid oedema and erythema that may extend beyond the region of the orbit itself to the cheek and surrounding face. It is often accompanied by a low grade fever. The eye itself is unaffected. In 95% of cases it is from local spread from a scratch, an insect bite or eczema. Occasionally it can arise from pre-existing dacrocystitis.
Peri-orbital cellulitis may be caused by Staph. aureus, Strep. pneumoniae or occasionally Haemophilus influenza in the unimmunised.
It can be hard to differentiate between orbital and peri-orbital cellulitis and the consequences of getting it wrong are quite severe. If there is any doubt then it should be treated as the more serious orbital cellulitis. Peri-orbital cellulitis responds well to amoxycillin-clavulanate or cephalexin.