Neonatal conjunctivitis is watery or purulent ocular drainage due to a chemical irritant or a pathogenic organism. Prevention with antigonococcal topical treatment at birth is routine. Diagnosis is clinical and usually confirmed by laboratory testing. Treatment is with organism-specific antimicrobials.
(See also Acute Bacterial Conjunctivitis and Overview of Neonatal Infections.)
Etiology of Neonatal Conjunctivitis
The major causes of neonatal conjunctivitis (in decreasing order) are
Bacterial infection
Chemical inflammation
Viral infection ( see also Overview of Conjunctivitis)
Infection is acquired from infected mothers during passage through the birth canal. Chlamydial ophthalmia (caused by Chlamydia trachomatis) is the most common bacterial cause; it accounts for up to 40% of conjunctivitis in neonates < 4 weeks of age. The prevalence of maternal chlamydial infection ranges from 2 to 20%. About 30 to 50% of neonates born to acutely infected women acquire infection, and 25 to 50% of those develop conjunctivitis (and 5 to 20% develop pneumonia). Other bacteria, including Streptococcus pneumoniae and nontypeable Haemophilus influenzae, account for another 30 to 50% of cases, whereas gonococcal ophthalmia (conjunctivitis due to Neisseria gonorrhoeae) accounts for < 1% of cases.
Chemical conjunctivitis is usually secondary to the instillation of topical therapy for ocular prophylaxis.
The major viral cause is herpes simplex virus types 1 and 2 (herpetic keratoconjunctivitis), but this virus causes < 1% of cases.
Symptoms and Signs of Neonatal Conjunctivitis
Because they overlap in both manifestation and onset, causes of neonatal conjunctivitis are difficult to distinguish clinically. Conjunctivae are injected, and discharge (watery or purulent) is present.
Chemical conjunctivitis secondary to topical prophylaxis usually appears within 6 to 8 hours after instillation and disappears spontaneously within 48 to 96 hours.
Chlamydial ophthalmia usually occurs 5 to 14 days after birth. It may range from mild conjunctivitis with minimal mucopurulent discharge to severe eyelid edema with copious drainage and pseudomembrane formation. Follicles are not present in the conjunctiva, as they are in older children and adults.
Gonococcal ophthalmia causes an acute purulent conjunctivitis that appears 2 to 5 days after birth or earlier with premature rupture of membranes. The neonate has severe eyelid edema followed by chemosis and a profuse purulent exudate that may be under pressure. If untreated, corneal ulcerations and blindness may occur.
Conjunctivitis caused by other bacteria has a variable onset, ranging from 4 days to several weeks after birth.
Herpetic keratoconjunctivitis can occur as an isolated infection or with disseminated or central nervous system infection. It can be mistaken for bacterial or chemical conjunctivitis, but the presence of dendritic keratitis is pathognomonic.
Diagnosis of Neonatal Conjunctivitis
Testing of conjunctival material for pathogens including gonorrhea, chlamydia, and, sometimes, herpes
Conjunctival material is Gram stained, cultured for gonorrhea (eg, on modified Thayer-Martin medium) and other bacteria, and tested for chlamydia (eg, by culture, direct immunofluorescence, or enzyme-linked immunosorbent assay [samples must contain cells]). Conjunctival scrapings can also be examined with Giemsa stain; if blue intracytoplasmic inclusions are identified, chlamydial ophthalmia is confirmed. Nucleic acid amplification tests may provide equivalent or better sensitivity for the detection of chlamydia from conjunctival material compared to older methods.
Viral culture is done only if viral infection is suspected because of skin lesions or maternal infection.
Treatment of Neonatal Conjunctivitis
Systemic, topical, or combined antimicrobial therapy
see Table: Recommended Dosages of Selected Parenteral Antibiotics for Neonates) before results of confirmatory tests are available.
In chlamydial ophthalmia,hypertrophic pyloric stenosis
A neonate with gonococcal ophthalmia
Corticosteroid-containing ointments may seriously exacerbate eye infections due to C. trachomatis and herpes simplex virus and should be avoided.
Prevention of Neonatal Conjunctivitis
Key Points
C. trachomatis, S. pneumoniae, and nontypeable H. influenzae cause most bacterial conjunctivitis; N. gonorrhoeae is a rare cause.
Conjunctivae are injected, and discharge (watery or purulent) is present.
Test conjunctival material for pathogens (including gonorrhea and chlamydia) using culture, and sometimes nucleic acid amplification tests.
Give antibiotics active against the infecting organism; neonates with gonococcal infection should be hospitalized.
Give systemic therapy for chlamydial ophthalmia.
