Description

This is a conjunctivitis occurring in the first 28 days of life.^[1] It is most commonly infective in origin: bacterial causes include Chlamydia trachomatis, Neisseria gonorrhoeae, Staphylococcus aureus, Streptococcus pneumoniae and various other organisms. Less often viral causes - notably the herpes simplex virus. It may also occur as a reaction to chemical irritants. The latter is a self-limiting condition lasting no more than 24 to 36 hours but infections need treatment. Its importance lies in the fact that it is potentially sight-threatening and may cause systemic complications.^[2] As of April 2010, ophthalmia neonatorum is no longer a notifiable disease.^[3]

Epidemiology

• It affects 1-2%^[4] (some report up to 12%)^[2] of infants in the western world, although this varies according to the socioeconomic status of the area.^[4] The figure goes up to 23% in developing countries.^[2]
• The main risk factor for ophthalmia neonatorum of infective origin is the presence of a sexually transmitted disease in the mother.^[2]
• There is a high rate of transmission from infected mother to infant.
• Chlamydia is the commonest cause of infective neonatal conjunctivitis.
• Cases of chemical conjunctivitis are decreasing as silver nitrate prophylaxis is being replaced by other agents (see 'Prevention', below) which in turn, have reduced the incidence of gonococcal conjunctivitis.

Presentation^[2][4]

Babies present with a purulent, mucopurulent or mucoid discharge from one or both eyes within the first month of life. Also, look for injected conjunctiva and lid swelling.^[5] There may be associated systemic infection.

• Chemical conjunctivitis - there is a mild irritation, tearing and redness in a baby who has been administered prophylactic silver nitrate (used for the prevention of gonorrhoeal infection) within the preceding 24-48 hours.
• Bacterial conjunctivitis - often (but not invariably) a longer incubation period than for the other infective causes, presenting with a subacute onset between the 4th and 28th day of life. Depending on the pathogen, there may be a mixed picture of a red eye with lid swelling and a varying amount of purulent discharge. Specific types of bacterial infection:
  • Chlamydial infection - 5 to 14 days after birth (some report up to 28 days after birth): unilateral/bilateral watery discharge which becomes copious and purulent later on. There may be associated preseptal cellulitis and, less commonly, rhinitis, otitis and pneumonitis.
  • Gonorrhoeal infection - typically 1-5 days after birth but may occur later: hyperacute conjunctival injection and chemosis, lid oedema and severe purulent discharge. There may be associated corneal ulceration and perforation.^[5]
• Viral conjunctivitis - onset is acute, 1-14 days after birth: unilateral/bilateral serosanguinous discharge ± vesicular skin lesions. Other ocular features may include keratitis, anterior uveitis, cataract, retinitis and, rarely, optic neuritis. Uncommonly, systemic infection can cause jaundice, hepatosplenomegaly, pneumonitis, meningoencephalitis and disseminated intravascular coagulation.

Differential diagnosis

A blocked nasolacrimal duct is common and results in a thick (sometimes copious) discharge which may be sticky or crusty. The eye is not red and the baby is otherwise well. The discharge may be intermittent and responds well to simple cleansing. Most babies' ducts clear as they grow, the majority being perfectly normal by 6-12 months of age.

Investigations

These are carried out in the Eye Unit and will include:

• History - previous or concurrent sexually transmitted disease in the mother and results of any cervical cultures obtained during pregnancy.
• Ocular examination - penlight and fluorescein examination.
• Microbiological investigations - conjunctival swabs (ideally obtained from the everted lid) and cultures including for chlamydial detection and viral cultures. The Gram staining is requested urgently where there is suspicion of gonococcal conjunctivitis. Even if gonorrhoeal infection is strongly suspected, investigation for chlamydia should be carried out and vice versa in the case of suspected chlamydial infection.
• Mother - she will need cervical swabs for gonorrhoea, chlamydia and viral infection and so will need to be seen at the genitourinary medicine clinic. There must also be efforts to trace sexual partners.^[5]

Management^[1]

Referral

The majority of neonates presenting with a sticky discharge have a benign cause - most frequently due to blocked nasolacrimal duct(s). Problems suggesting that referral is necessary include:

• If the conjunctiva is red, especially if the bulbar conjunctiva (overlying the sclera) is red.
• If the onset is sudden and severe.
• If the baby is distressed or unwell.
• If both eyes are affected.
• If there are suspicions of a possible maternal infection.
• If the mother is concerned, or you are concerned.

If you suspect ophthalmia neonatorum, refer immediately. Early and appropriate treatment has long been recognised as the key to preventing consequent blindness.

Initial therapy^[5]

Prior to results from Gram staining (or if these are inconclusive), it is appropriate to start the infant on a broad-spectrum antibiotic eg ofloxacin 0.3% qds for a week until the microbiological results have come back.

Chemical conjunctivitis

No treatment is required, although some favour the use of preservative-free artificial tears qds. These babies need early review (24 hours) to confirm that this was indeed a case of chemical irritation as opposed to early infection.

Bacterial infection

Treatment should be guided by the organism grown. If there is corneal involvement, the baby may be hospitalised and treated as for microbial keratitis.

Chlamydial infection

Oral erythromycin syrup (50 mg/kg/day in four divided doses) for 14 days. Topical treatment alone is not sufficient and is not necessary when systemic treatment is taken. The mother and her sexual partners will also need treating.

Gonorrhoeal infection

These babies need hospitalisation and evaluation for disseminated disease. There is no established treatment protocol but options include ceftriaxone (single dose: 25-50 mg/kg intravenously (IV) or intramuscularly (IM), no more than 125 mg in total) or cefotaxime (single dose: 100 mg/kg IV or IM). If there is penicillin or cephalosporin allergy, the infectious disease consultant will need to be involved. Additionally, these infants can be treated with bacitracin eye ointment 2- to 4-hourly and topical saline lavages to remove the discharge (qds). They should be concurrently treated for chlamydial infection, as above.

Viral infection

These babies should be hospitalised and treated with IV aciclovir (full-term infants: 45-60 mg/kg/day in 3 doses for 14 days if limited disease and 21 days if disseminated disease) as well as topical antiviral preparations.

Complications

• Keratitis.
• Conjunctival scarring.
• Superior corneal pannus.
• Rarely - side-effects of treatment, such as the association between oral erythromycin and infantile hypertrophic pyloric stenosis (IHPS) reported in infants aged <6 weeks.^[6]
• Rarely - effects of overwhelming systemic infection (consider chlamydial pneumonia, for example).
• Pseudomonas spp. infection is very rare but may be devastating, causing keratitis; in disseminated cases, it can ultimately lead to death.

If the initial infection recurs, chlamydia should be reconsidered (even if the baby first tested negative).^[5]

Prognosis

• Chlamydial infection: good - 80% fully recover after one course of treatment.^[6]
• Bacterial infection: rarely fails to respond to appropriate treatment.^[4]
• Viral infection: the ocular prognosis can be poor and the systemic sequelae may be fatal.
• Chemical irritation: good - full spontaneous recovery expected after 24-36 hours.

Prevention^[7]

The issue of prevention tends to relate to those infections acquired during vaginal deliveries in mothers known to have either chlamydial or gonorrhoeal infection. Traditionally, this has involved the use of 2% silver nitrate ophthalmic solution but erythromycin and tetracycline have also been used for prophylaxis against gonorrhoeal infection.^[8] More recently, there have been advocates of the additional application of 2.5% povidone-iodine ophthalmic solution which is more effective than the other agents, especially against chlamydial infection, and does not appear to have systemic side-effects.^[9]

A recent meta-analysis looked at routine eye prophylaxis in all babies and concluded that, where the prevalence of maternal infection is low, it is probably not worthwhile due to the high failure rates of the prophylactic regime.^[8] This remains the remit of specialist care.