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Neonatal conjunctivitis is purulent ocular drainage due to a chemical irritant or a pathogenic organism. Prevention with antigonococcal drops at birth is routine. Diagnosis is clinical and usually confirmed by laboratory testing. Treatment is with organism-specific antimicrobials.
Etiology
The major causes (in decreasing order) are
Chemical conjunctivitis is generally secondary to the instillation of silver nitrate drops for ocular prophylaxis. Bacterial infection is acquired from infected mothers during passage through the birth canal. Chlamydial ophthalmia (caused by Chlamydia trachomatis) is the most common bacterial cause, occurring in 2 to 4% of births; it accounts for about 30 to 50% of conjunctivitis in neonates < 4 wk of age. The prevalence of maternal chlamydial infection ranges from 2 to 20%. About 30 to 50% of neonates born to acutely infected women develop conjunctivitis (and 5 to 20% develop pneumonia). Other bacteria, including Streptococcus pneumoniae and nontypeable Haemophilus influenzae, account for another 15% of cases. The incidence of gonorrheal ophthalmia (conjunctivitis due to Neisseria gonorrhoeae) in the US is 2 to 3/10,000 births. Isolation of bacteria other than H. influenzae, S. pneumoniae, and N. gonorrhoeae, including Staphylococcus aureus, usually represents colonization rather than infection. The major viral cause is herpes simplex virus types 1 and 2 (herpetic keratoconjunctivitis).
Symptoms and Signs
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 silver nitrate usually appears within 6 to 8 h after instillation and disappears spontaneously within 48 to 96 h.
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.
Gonorrheal 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.
Herpetic keratoconjunctivitis can occur as an isolated infection or with disseminated or CNS infection. It can be mistaken for bacterial or chemical conjunctivitis, but the presence of dendritic keratitis is pathognomonic.
Diagnosis
Conjunctival material is Gram stained, cultured for gonorrhea (eg, on modified Thayer-Martin medium), 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. Viral culture is done only if viral infection is suspected because of skin lesions or maternal infection.
Treatment
Neonates with conjunctivitis and known maternal gonococcal infection or with gram-negative intracellular diplococci identified in conjunctival exudates should be treated with ceftriaxone before results of confirmatory tests are available.
In chlamydial ophthalmia, systemic therapy is the treatment of choice, because at least half of affected neonates also have nasopharyngeal infection and some develop chlamydial pneumonia. Erythromycin ethylsuccinate 10 mg/kg po q 6 h for 2 wk is recommended. Efficacy of this therapy is only 80%, so a 2nd treatment course may be needed. Because use of erythromycin in neonates is associated with the development of hypertrophic pyloric stenosis (HPS—see Gastrointestinal Disorders in Neonates and Infants: Hypertrophic Pyloric Stenosis), all neonates treated with erythromycin should be monitored for symptoms and signs of HPS.
A neonate with gonorrheal ophthalmia is hospitalized to be evaluated for possible systemic gonococcal infection and given a single dose of ceftriaxone 25 to 50 mg/kg IM to a maximum dose of 125 mg (infants with hyperbilirubinemia or those receiving Ca-containing fluids may be given cefotaxime 100 mg/kg IV or IM). Frequent saline irrigation of the eye prevents secretions from adhering. Topical antimicrobial ointments alone are ineffective.
Conjunctivitis due to other bacteria usually responds to topical ointments containing polymyxin plus bacitracin, erythromycin, or tetracycline.
Herpetic keratoconjunctivitis should be treated (with an ophthalmologist's consultation) with systemic acyclovir 20 mg/kg q 8 h for 14 to 21 days and topical 1% trifluridine ophthalmic drops or ointment, vidarabine 3% ointment, or 0.1% iododeoxyuridine q 2 to 3 h, with a maximum of 9 doses/24 h. Systemic therapy is important, because dissemination to the CNS and other organs can occur.
Corticosteroid-containing ointments may seriously exacerbate eye infections due to C. trachomatis, and herpes simplex virus and should be avoided.
Prevention
Routine use of 1% silver nitrate drops, 0.5% erythromycin, or 1% tetracycline ophthalmic ointments or drops instilled into each eye after delivery effectively prevents gonorrheal ophthalmia. However, none of these agents prevents chlamydial ophthalmia; povidone iodine 2.5% drops may be effective against chlamydia and is effective against gonococci but is not available in the US. Silver nitrate and tetracycline ophthalmic ointments are also no longer available in the US.
Neonates of mothers with untreated gonorrhea should receive a single injection of ceftriaxone 25 to 50 mg/kg IM or IV, up to 125 mg, and both mother and neonate should be screened for chlamydia infection, HIV, and syphilis.
Last full review/revision October 2009 by Mary T. Caserta, MD
Content last modified February 2012
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