Diagnosis: Chlamydial ophthalmia neonatorum
Ophthalmia neonatorum (ON), or neonatal conjunctivitis, commonly referred to as “pink eye,” is broadly defined as any inflammation of the conjunctiva (membrane covering the surface of the eyeball) during the first month of life. It is a serious cause of corneal perforation and blindness in neonates if left untreated Table 1 lists possible etiologies of ON, which can often be determined from onset of symptoms. ON can be acquired secondary to medications or from infectious exposure in utero or during delivery. Presently, the most common cause of ON in the United States is due to chlamydia trachomatis, which comprises up to 40% of cases.
Table: Possible causes of ophthalmia neonatorum by time of onset
|Onset from Birth||Etiology||Additional Notes|
|0-24 hours||Chemical conjunctivitis||Arises from use of prophylactic eye drops . Common causes include silver nitrate > erythromycin > gentamicin drops|
|24-48 hours*||Bacterial conjunctivitis*||Neisseria gonorrhoeae (though less common in U.S. because of routine prophylactic erythromycin); Staphylococcus aureus;|
|5-14 days||Chlamydia trachomatis||Most common cause of ON in the U.S.|
|6-14 days||Herpes keratoconjunctivitis|
|5-18 days||Pseudomonas aeruginosa conjunctivitis||Rare, preterm infants or infants requiring invasive procedures are most at risk.|
|Other causes||Streptococcus pneumoniae, nontypeable Haemophilus influenzae|
*Though commonly occurring within 48 hours of birth, bacterial conjunctivitis can occur at any time.
Major risk factors include vertical transmission through the birth canal, silver nitrate exposure, poor prenatal care, lack of ocular prophylaxis after birth, and maternal HIV infection. Neonatal tears also lack IgA making them susceptible to conjunctivitis.
Symptoms depend on etiology of ON and range from itching, burning, foreign body sensations, exudate, and other signs of inflammation including hyperemia, epiphora, chemosis, eyelid swelling, and pseudomembrane formation. Chemical conjunctivitis tends to be a more mild self-limiting cause of ON and is associated with epiphora. Chlamydia trachomatis tends to produce a watery discharge initially that may progress to purulent discharge. They have mild to moderate signs of inflammation. ON from Neisseria gonorrhoeae can produce a severe mucopurulent discharge and is often associated with severe eyelid swelling and chemosis. Prompt diagnosis and treatment of Neisseria gonorrhoeae are essential as corneal perforation can occur within two days of onset. HSV conjunctivitis can present with non-purulent serosanguineous discharge with moderate edema. Herpetic vesicles on the eyelid or microdendrites or ulcers near the cornea may also be observed. Lastly, pseudomonas aeruginosa conjunctivitis presents with mucopurulent discharge and can progress to corneal involvement with perforation or ulceration.
Other associated symptoms can provide a clue in regard to etiology. Concurrent otitis media tends to arise with ON secondary to H. influenzae or Streptococcus while viral causes often are accompanied with pharyngitis, rhinorrhea and cervical adenopathy. Infants with chlamydial ON may have concurrent pneumonitis or systemic symptoms. In addition, the appearance of conjunctivitis on the exam can also differ by etiology. Viral or intracellular infections such as Chlamydia trachomatis result in a follicular pattern of conjunctivitis due to hypertrophy of lymphoid tissue. Meanwhile, extracellular bacterial infections tend to cause a papillary reaction.
As many other eye conditions can also present with conjunctivitis, it is important to maintain a broad differential. Other conditions that may occur in a newborn with pink eye and/or discharge include:
- Allergic conjunctivitis
- Nasolacrimal duct obstruction (tear duct often takes a while to open in newborns)
- Dacryocystitis (infection of tear sac)
- Trichiasis (inward turning of eyelashes can cause irritation)
- Foreign body
- Congenital glaucoma
- Corneal abrasion
Work-up for ON includes anterior eye segment examination. Examination should also occur under fluorescein and blue cobalt light to detect corneal involvement or herpes keratitis conjunctivitis. For infectious etiologies, lab testing such as Gram stain, cultures, nucleic acid amplification tests, PCR or antibody testing should be performed.
Treatment and duration is based on the source of ON and extent of disease. Prompt diagnosis and initiation of treatment can result in an excellent prognosis. For chlamydial ON, treatment is with oral erythromycin syrup. Gonorrheal ON is treated with ceftriaxone and erythromycin ointment. Lavage with normal saline can be used to remove discharge. HSV keratoconjunctivitis is treated with acyclovir and vidarabine ointment. Silver nitrate and viral forms of conjunctivitis are self-limiting and are treated with supportive care.
The United States Preventive Services Task Force recommends prophylaxis against gonococcal ON for all newborns as part of their newborn examination. Standard prophylactic treatment for gonococcal ON is erythromycin ophthalmic ointment, which should be administered within two hours of delivery. Silver nitrate is another prophylactic alternative but tends to cause higher rates of chemical conjunctivitis. Currently, there is no prophylaxis available for neonatal chlamydial conjunctivitis, so screening and treatment of sexually transmitted infections during pregnancy remains the best method of protection. Pregnant women with active lesions from genital herpes should avoid vaginal delivery.
Of note, Chlamydia trachomatis serotype A-C may also cause trachoma and is an important cause of progressive blindness in children and adults in developing countries. It is characterized by white lumps (follicles), often located at the limbus or conjunctival surface adjacent to the upper eyelid. These follicles can later resolve and form “Herbert pits” or shallow depressions at the limbus. Severe scar tissue may also arise leading to “cicatricial trachoma.” Extent of scarring can result in the appearance of an Arlt line from scarring of the tarsal conjunctiva, trichiasis, and corneal opacification. End stage trachoma results in vision loss. Treatment includes prolonged oral and topical antibiotics.
References and Additional Resources:
- Richards A, Guzman-Cottril JA. Conjunctivitis. Pediatrics in Review. 2010;31(5):196-207.
- Bowman KM. Epley KD, Prakalapakorn SG. Prabhu S. Neonatal conjunctivitis. Prabhu S (Eds). American Academy of Ophthalmology: EyeWiki. July 2020.
- Makker K, Nassar GN, Kaufman EJ. Neonatal Conjunctivitis. [Updated 2020 Dec 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441840/.
- Shah SS, Gloor P, Gallagher PG. Bacteremia, meningitis, and brain abscesses in a hospitalized infant: complications of Pseudomonas aeruginosa conjunctivitis. Journal of Perinatology. 1999;19(6):462-5.
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