A 10-day-old male infant is brought to the pediatrician by his mother because of bilateral eye redness and discharge for the past day. The infant was born at home via spontaneous vaginal delivery to a mother who received limited prenatal care. The infant's temperature is 37.2°C (99.0°F). On physical examination, the eyelids are significantly edematous, and the palpebral conjunctivae appear thickened and erythematous. There is a moderate amount of watery, mucopurulent discharge from both eyes. No corneal opacities are noted. The lungs are clear to auscultation. A Gram stain of the conjunctival scrapings shows no organisms, but a Giemsa stain reveals several intracellular inclusions.
Which of the following is the most appropriate next step in the management of this patient?
The correct answer is:
C) Oral erythromycin
The clinical presentation and the presence of intracellular inclusions on Giemsa stain are diagnostic of neonatal chlamydial conjunctivitis caused by Chlamydia trachomatis serotypes D–K. This typically presents 5 to 14 days after birth with eyelid swelling, chemosis, and mucopurulent discharge. Unlike many other forms of neonatal conjunctivitis, chlamydial infection requires oral macrolide therapy (e.g., erythromycin or azithromycin). Systemic treatment is necessary because topical therapy has high failure rates and, more importantly, because these infants are at high risk for developing chlamydial pneumonia. When using oral erythromycin in neonates, clinicians must monitor for the potential side effect of infantile hypertrophic pyloric stenosis.
Answer choice A: Intramuscular ceftriaxone, is incorrect. This is the treatment of choice for gonococcal conjunctivitis caused by Neisseria gonorrhoeae. Gonococcal conjunctivitis usually presents more acutely, typically 2–5 days after birth and is characterized by significantly more profuse, purulent discharge and the risk of corneal perforation. Gram stain would show Gram-negative diplococci.
Answer choice B: Intravenous acyclovir, is incorrect. This is used for neonatal herpes simplex virus (HSV) infections. HSV conjunctivitis typically presents within the first two weeks of life and is often associated with vesicular skin lesions, keratitis, or systemic involvement.
Answer choice D: Topical erythromycin, is incorrect. Topical erythromycin ointment is the standard prophylaxis administered to all newborns shortly after birth to prevent gonococcal ophthalmia neonatorum. However, it is not an effective treatment for an active chlamydial infection, nor does it reliably prevent chlamydial conjunctivitis.
Answer choice E: Topical silver nitrate, is incorrect. Silver nitrate was historically used for gonococcal prophylaxis but can cause chemical conjunctivitis. Chemical conjunctivitis typically presents within the first 24 hours of life and is characterized by mild conjunctival injection and tearing that resolves spontaneously.
Key Learning Point
Neonatal chlamydial conjunctivitis typically presents 5–14 days after birth with mucopurulent discharge and chemosis. Diagnosis is confirmed by a nucleic acid test (NAT) or the presence of cytoplasmic inclusions on Giemsa-stained scrapings. The most appropriate management is oral macrolide therapy to treat the ocular infection and prevent the development of chlamydial pneumonia.
