Bacterial conjunctivitis: A review for internists
ABSTRACTBacterial conjunctivitis is common and occurs in patients of all ages. Typical signs are a red eye and purulent drainage that persists throughout the day. Gonococcal and chlamydial conjunctivitis must be treated with systemic antibiotics. Bacterial conjunctivitis due to most other organisms can be treated empirically with topical antibiotics. Red flags suggesting a complicated case requiring referral to an ophthalmologist include reduced vision, severe eye pain, a hazy-appearing cornea, contact lens use, and poor response to empirical treatment.
KEY POINTS
- Viral conjunctivitis typically presents as an itchy red eye with mild watery discharge. Many patients have signs and symptoms of a viral upper respiratory tract infection (eg, cough, runny nose, congestion) and have been in contact with a sick person.
- Having both eyes glued shut in the morning had an odds ratio of 15:1 in predicting a positive bacterial culture, whereas either itching or previous conjunctivitis made a bacterial cause less likely.
- In adults, Neisseria gonorrhoeae causes hyperacute conjunctivitis and is associated with concurrent, often asymptomatic genital infection. Gonococcal conjunctivitis should be treated with a single dose of ceftriaxone (Rocephin) 1 g intramuscularly plus saline eye-washing.
- Corticosteroid drops should not be prescribed for a red eye before consultation with an ophthalmologist because these drops may worsen some conditions.
Topical antibiotics hasten cure
Other types of bacterial conjunctivitis usually resolve spontaneously: early placebo-controlled studies found that more than 70% of cases of bacterial conjunctivitis resolve within 8 days.25 However, treatment with antibacterial agents leads to a faster clinical and microbiological cure26 and reduces the chance of rare complications27 and of transmitting the infection.
Is culture necessary?
A predictable set of organisms accounts for most cases of bacterial conjunctivitis in outpatients, so many physicians start therapy empirically without culturing the conjunctiva. But in the hospital the organisms and their antibiotic resistance patterns are more varied, so culturing the conjunctiva before starting broad-spectrum therapy may be warranted.15 For an outpatient with possible hyperacute conjunctivitis, it is reasonable to perform a Gram stain in the office if the facilities exist, but it is not essential because urgent referral to an ophthalmologist is warranted regardless of the results to rule out corneal involvement.
Unfortunately, antibiotic resistance is increasing even among outpatients. Susceptibility of the most common ocular pathogens to ophthalmic antimicrobial agents has dropped dramatically: S pneumoniae and S aureus have developed high rates of resistance.30 Recent data also suggest that treatment with topical ophthalmic antibiotics can induce resistance among colonizing bacteria in nonocular locations.31 Widespread systemic treatment with azithromycin or tetracycline for control of endemic trachoma in two villages in Nepal resulted in increased rates of antibiotic resistance among nasopharyngeal isolates of S pneumoniae. S aureus is developing resistance to methicillin and to fluoroquinolones, such as levofloxacin (Levaquin).32,33 But fluoroquinolones are still effective against most bacteria that cause conjunctivitis or keratitis, and because they penetrate the cornea well, they should be used if clinical features suggest corneal involvement. Remember also that most patients recover without treatment even if the organism has appreciable antibiotic resistance.28
Corticosteroids should be avoided
Although corticosteroid drops (either alone or combined with antibiotic drops) may quickly relieve symptoms, some conditions that present as a red eye with watery discharge, such as herpetic keratitis, worsen with corticosteroid use. We recommend that internists avoid prescribing corticosteroid drops.
Remove contact lenses, replace eye drops
Contact lenses should be taken out until an infection is completely resolved. Disposable lenses should be thrown away. Nondisposable lenses should be cleaned thoroughly as recommended by the manufacturer, and a new lens case should be used.
Patients who use prescription eye drops for glaucoma should continue to use them, but the bottles should be replaced in case they have been contaminated by inadvertent contact with the eye.
Over-the-counter lubricating eye drops may be continued if desired, but a fresh bottle or vial should be used.
WHEN TO REFER
Red flags indicating that a patient may have a serious vision-threatening condition that requires urgent referral to an ophthalmologist include severe eye pain or headache, photophobia, decreased vision, or contact lens use. Patients with hyperacute cases should also be referred at once to rule out corneal involvement, although the internist should start treatment for gonorrhea. In addition, patients with apparent bacterial conjunctivitis that does not improve after 24 hours of antibiotic treatment should also be referred to an ophthalmologist.
