Figures 1A (left) and 1B (right). CT scan of the orbits reveals a multiloculated subperiosteal abscess
Dr Ashley Kras
Ophthalmology registrar, Royal Children’s Hospital and Royal Victorian Eye and Ear Hospital Melbourne
Dr Susan M Carden
MBBS FRANZCO FRACS PhD
Consultant ophthalmologist, Royal Children’s Hospital and Royal Victorian Eye and Ear Hospital Melbourne
Senior lecturer, Department of Paediatrics Royal Children’s Hospital.
Rooms: Bentleigh VIC
AK presented to the emergency department with a 24-hour history of unilateral left eyelid swelling. Initially he was diagnosed with preseptal orbital cellulitis and discharged with chloramphenicol 0.5% one drop qid to the left eye and fluorometholone 0.1%, one drop qid to left eye.
One day later, he re-presented with increased left eyelid oedema, and a fever of > 38 degrees Celsius. Laboratory results showed an increased white cell count of 14.9 x 109/L (neutrophils 11.7 x 109/L) and an increased C-reactive protein level of 42 mg/L. The working diagnosis was changed to orbital cellulitis. Systemically, he seemed well and an examination revealed no other abnormalities.
He was admitted to hospital and treated with intravenous antibiotics. After discussion with the infective diseases team, he was given intravenous ceftriaxone and flucloxacillin (each 50 mg/kg).
A CT scan of his orbits (Figures 1A and 1B) revealed a multiloculated subperiosteal abscess (30 x 8 x 12 mm AP x transverse x cranio-caudal) along the medial wall of the left orbit and extending from the medial canthus posteriorly to the orbital apex. This exerted a mass effect on the intraorbital structures, causing crowding at the orbital apex and proptosis.
The abscess was considered to be a probable complication of asymptomatic extensive sinonasal inflammatory disease.
Within 24 hours, AK was taken to theatre and under general anaesthetic, the abscess was drained by the ear, nose and throat team via a nasal approach. Intraoperative eye examination did not reveal any optic nerve swelling. Postoperatively he recovered well.
An intraoperative pus swab grew Haemophilus influenza (not type B), which was sensitive to ampicillin and cefotaxime. Blood cultures did not yield any bacterial growth. At day two postoperatively, the infectious diseases team rationalised his antibiotic therapy to single therapy ceftriaxone,1 which continued for five days in total. On day three postoperatively, he was discharged under the care of the ‘Hospital in the Home’ service.
After two days at home, the left eyelid became swollen again. A second CT scan (Figure 2) revealed a left medial orbital wall subperiosteal collection, which could either represent a residual abscess or a recurrence of the original abscess. Despite its smaller size (23 x 5 x 23 mm), this collection caused a marked mass effect on the intraorbital structures. There was a new soft tissue abscess in the left lower eyelid measuring 7 x 14 x 7 mm.
Figure 2. A second CT scan, performed after the initial drainage, revealed a left medial orbital wall subperiosteal collection. This could represent either a residual abscess or a recurrence of the original abscess
Intravenous cefotaxime was commenced. The ear, nose and throat team again drained the collection under general anaesthetic, via the same nasal approach. In addition to the antibiotic treatment, AK received 48 hours of intravenous dexamethasone treatment (0.15 mg/kg) to reduce the eyelid swelling.
Five days after the second abscess drainage, AK was discharged home on oral Augmentin. He had some residual diplopia that was improving and was thought to be due to residual orbital swelling. The ophthalmic examination was otherwise unremarkable.
This case highlights the importance of early and accurate diagnosis of orbital cellulitis, which can be sight- and even life-threatening.2 This is in contrast to the more common preseptal cellulitis, which affects subcutaneous tissue anterior to the orbital septum. Preseptal cellulitis is often caused by minor skin trauma, such as lacerations, insect bites or acute hordeolae.
Orbital cellulitis, affecting tissues deep to the orbital septum, commonly originates in the paranasal sinuses. It can also progress from preseptal cellulitis, dacryocystitis or dental infections.
Key clinical signs that may suggest orbital cellulitis include proptosis, chemosis, conjunctival injection and painful ophthalmoplegia; and optic nerve dysfunction such as reduced visual acuity, reduced colour vision or a relative afferent pupillary defect.
1. Therapeutic Guidelines: Eye infections [Internet]. eTG (electronic Therapeutic Guidelines) complete. 2015 [cited 11 July 2016]. Available from: https://tgldcdp.tg.org.au/viewTopic?topicfile=eye-infections#toc_d1e142.
2. Bowling B. Kanski’s Clinical Ophthalmology. 8th ed. Elsevier, 2016.