Sir,

Orbital cellulitis requires prompt diagnosis and treatment to prevent visual or life-threatening complications. We report an unusual case and cause of orbital cellulitis in a 3-year-old, managed conservatively with a good outcome visually and systemically.

Case report

A 3-year-old boy presented to the accident and emergency department with a 3-day history of cough and cold, a 1 day history of right periorbital swelling and drowsiness. The periorbital swelling had increased dramatically in a 24-h period preceding admission associated with systemic features of fever (38.5°C), nausea, and malaise. Ophthalmology review revealed a tense orbit with periorbital erythema and oedema, with 5 mm of nonaxial proptosis with a hypotropic and exodeviated eye. There was marked conjunctival injection with some chemosis, with no evidence of corneal exposure. There was no relative afferent pupillary defect and no evidence of disc swelling. Ocular motility was restricted in all directions of gaze more marked on dextro depression. Serological investigations including a full blood count revealed a moderate leucocytosis and blood cultures were taken on presentation. Axial and coronal CT scanning of the orbit and brain revealed extensive ethmoidal and maxillary sinusitis, marked periorbital soft tissue enhancement and proptosis, and an area suspicious for enhancement in the right frontal lobe of the brain. Initial antibiotic therapy of i.v. augmentin and flucloxacillin was changed to i.v. piperacillin and gentamicin upon microbiology review. Neurosurgical and ENT review recommended conservative therapy. On review, 1/7 postadmission, the proptosis had lessened to 4 mm. On review, day 3 of admission, there was reduced proptosis (3 mm) and a recovering range of ocular motility. A repeat CT (Figure 1) scan revealed a large subperiosteal abscess with intraorbital emphysema, with resolution of the previously suspicious area for enhancement in the right frontal lobe. The presence of intracranial free air in the frontal lobe was demonstrated. Review day 4 showed continued improvement on i.v. piperacillin and gentamicin. Continued neurosurgical and ENT review advised conservative management. The patient continued to improve systemically and clinically over the next 2 days with the proptosis measuring 2.5 mm. Visual acuity assessment was 3/3 on Kays picture acuity cards throughout. On day 7, blood culture (taken on admission) isolated Kingella kingae microorgansism sensitive to piperacillin and gentamicin (Figure 2). The patient continued to improve and was discharged on day 11 with 1.5 mm proptosis, increasing range of extraocular movements and visual acuity of 3/3 on Kays pictures. Systemic examination was normal. On examination at 1 month, the proptosis had fully resolved with a full range of extraocular movements and normal visual acuity.

Figure 1
figure 1

Reconstructed coronal CT scan showing surgical emphysema in R supero-lateral orbit (white arrow) and dense ethmoidal sinusitis (black arrow). Note also intracranial gas in the right frontal lobe. Note clear sinus on the contralateral side.

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Figure 2
figure 2

Kingella kingae microorganism on Gram stain.

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Comment

Orbital cellulitis is potentially a life- and sight-threatening disease, and in the preantibiotic era the mortality rate was 17 and 20% of the survivors were blind in the affected eye.1 Complications can include loss of vision secondary to optic nerve compression or exudative retinal detachment, cavernous sinus thrombosis, meningitis, and intracerebral abscess formation.2 The disease starts in the ethmoid sinus in children (poor development of other sinuses) and the infection spreads into the subperiosteal lining of the orbit through the ethmoid, leading to subperisosteal abscess formation. Affected children tend to be ill systemically, have a significant fever, and all will have radiographic evidence of sinusitis, particularly the ethmoid on the affected side. Pain on eye movement, pain on touch, proptosis, and restriction of extra-ocular muscles are late signs of disease. The subperiosteal abscess is often mananged conservatively in children in contrast to adults, unless the patient develops signs of a compressive optic neuropathy or exposure keratopathy.3 The most common microorganisms causing orbital cellulitis are H. influenza, streptoccus, staphyloccus, or diploccus.

Blood culture at day 7 in the above case isolated K. kingae. K. kingae is a short Gram-negative medium-sized coccus or rod with tapered ends exhibiting features of B-haemolyis, with an aerobic or facultative anaerobic metabolism.4 There are four known species of Kingella (K. indologenes, K. dentrificans, K. oralis and K. kingae). They are rare causes of human disease with a recent increase in pathogenecity due to improved isolation techniques.5, 6 They are very slow-growing and fastidious microorganisms and colonise the throat of young children especially males from 6 months to 4 years. There are seasonal peaks of incidence in winter and autumn, and clinically commonly cause skeletal infections in long bones, endocarditis, and bacteraemia. There have been no reports in the literature of K. kingae causing orbital cellulitis. Isolating the microorganism from peripheral blood indicates a substantial inoculum and is not isolated as a commensal organism.7

Two previous reports isolated K. kingae from a corneal scraping in a case of endo-ophthalmitis.8 No reports pertaining to orbital cellulitis have been reported. We report an unusual cause of orbital cellulutis in a 3-year-old. With improved isolation techniques, this organism as a potential cause of orbital disease needs to be investigated, especially when one considers the potential cardiac and other bony associations, including septic arthritis, osteomyelitis, dactylitis, and infective endocarditis.