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Preseptal and Postseptal Cellulitis
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Preseptal cellulitis is an infection of the periorbital tissues, whereas postseptal cellulitis involves the orbit. These disease entities occur mostly in patients < 10 years of age. They may present nearly identically with typical symptoms of erythema, warmth, tenderness to palpation. In preseptal cellulitis, the visual acuity and pupillary responses are normal, and there is the complete absence of any pain with extraocular movements, proptosis, and diplopia. If any of these characteristics are present, or if there is concern about postseptal involvement, then a CT scan (or MRI) of the orbit (axial and coronal views, with and without contrast) should be obtained to rule out orbital involvement. Preseptal cellulitis in nontoxic patients may be treated as an outpatient with amoxicillin/clavulanic acid (20 milligrams/kilogram PO divided every 12 hours; 500 milligrams PO tid in adults) with 24 hours follow-up with an ophthalmologist. In preseptal cellulitis in children <5 years or adults with significant comorbidities or in cases of postseptal cellulitis, an emergent ophthalmology consultation for admission should be obtained. Empiric intravenous therapy should begin with cefuroxime (50 milligrams/kilogram IV every 8 hours) or ceftriaxone (50 milligrams/kilogram every 12 hours), or ampicillin-sulbactam (50 milligrams/ kilogram IV every 6 hours), with IV vancomycin added if MRSA is suspected.
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Stye (External Hordeolum) and Chalazion
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A stye or external hordeolum, is an acute infection of an oil gland at the lash line that appears as a pustule at the lid margin. A chalazion is an acute or chronic noninfectious inflammation of the eyelid secondary to meibomian gland blockage in the tarsal plate. When it is acute, a chalazion may be painful, but is usually painless when chronic. A stye or acute chalazion is treated with warm, wet compresses 4 times daily and with erythromycin 0.5% ophthalmic ointment twice daily for 7 to 10 days. Persistent or recurrent lesions should be referred to an ophthalmologist for further evaluation and treatment.
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Bacterial Conjunctivitis
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Bacterial conjunctivitis presents as eyelash matting, mild to moderate mucopurulent discharge, and conjunctival inflammation. Fluorescein staining of the cornea should be performed in patients with suspected conjunctivitis to avoid missing abrasions, ulcers, and dendritic lesions. Topical antibiotics (Table 149-1) are appropriate. In children, Haemophilus influenza and Moraxella catarrhalis are considerations; therefore, if erythromycin ointment is ineffective, a change in antibiotics should be initiated. Contact lens wearers should receive topical antibiotic coverage for Pseudomonas, such ciprofloxacin or tobramycin. The lens should be discarded and not replaced until the infection has completely resolved. In patients younger than 2 months, sulfacetamide 10% solution 1 drop every 2 to 3 hours for 5 to 7 days may be used. Gentamicin has fallen out of favor due to the high incidence of ocular irritation.
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