A 6-year-old boy is brought to the office due to eyelid swelling. His mother noted a mosquito bite below his left lower eyelid 2 days ago. He developed mild swelling and redness of the lid yesterday and awoke today with his left eye swollen shut. He had a fever this morning that was relieved with acetaminophen. The patient has also had decreased energy and took naps after breakfast and lunch yesterday, which was unusual. Temperature is 38.3 C (101 F). The left lower eyelid is erythematous, edematous, and tender to palpation. Visual acuity is 20/20 in both eyes. The pupils are equal, round, and reactive. There is limited left eye adduction; the right eye has a normal range of motion. Laboratory results are as follows:
| Complete blood count | ||
| Hemoglobin | 12.8 g/dL | |
| Platelets | 200,000/mm3 | |
| Leukocytes | 18,000/mm3 | |
Which of the following is the most concerning finding in this patient?
Preseptal vs orbital cellulitis | ||
Diagnosis | Preseptal cellulitis | Orbital cellulitis |
Clinical features |
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PLUS
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Treatment |
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EOM = extraocular movements. | ||
Orbital cellulitis is a serious bacterial infection located posterior to the orbital septum and involves the muscles of extraocular movement. This infection usually results from contiguous extension from another source of infection (eg, sinusitis, dental abscess, preseptal cellulitis). Patients often have leukocytosis and eyelid edema and erythema. A clinical diagnosis is based on signs of extraocular muscle involvement, such as painful extraocular movements or ophthalmoplegia (ie, eye muscle weakness or paralysis), as shown in this patient with limited left eye adduction. Additional signs include visual changes (eg, poor acuity, diplopia) and proptosis.
Treatment is intravenous antibiotics and, if an abscess is present, surgical drainage. Severe complications include permanent visual impairment (eg, optic nerve involvement) and intracranial extension (eg, infection, cavernous sinus thrombosis).
(Choices A, B, C, and D) Preseptal cellulitis is a mild infection of the eyelid anterior to the orbital septum and most commonly results from local trauma (eg, insect bite, wound). Fever, leukocytosis, and eyelid edema and erythema may be present, as with orbital cellulitis; however, signs of extraocular muscle involvement are not present. This patient's orbital cellulitis may have progressed from initial preseptal cellulitis due to the mosquito bite.
Educational objective:
Orbital cellulitis can be differentiated from preseptal cellulitis by the presence of pain with extraocular movements, visual changes, proptosis, or ophthalmoplegia. Orbital cellulitis is a severe infection that can lead to permanent visual impairment or intracranial complications (eg, infection, thrombosis).