Neonatal conjunctivitis is a form of conjunctivitis (inflammation of the outer eye) which affects newborn babies following birth. It is typically due to neonatal bacterial infection, although can also be non-infectious (e.g. chemical exposure). Infectious neonatal conjunctivitis is typically contracted during vaginal delivery from exposure to bacteria from the birth canal, most commonly Neisseria gonorrhoeae or Chlamydia trachomatis. Antibiotic ointment is typically applied to the newborn's eyes within 1 hour of birth as prevention for gonococcal ophthalmia. This practice is recommended for all newborns and most hospitals in the United States are required by state law to apply eye drops or ointment soon after birth to prevent the disease. If left untreated, neonatal conjunctivitis can cause blindness. Signs and symptoms Neonatal conjunctivitis by definition presents during the first month of life. Signs and symptoms include: Pain and tenderness in the eyeball Conjunctival discharge: purulent, mucoid or mucopurulent (depending on the cause) Conjunctival hyperaemia and chemosis, usually also with swelling of the eyelids Corneal involvement (rare) may occur in herpes simplex ophthalmia neonatorum Time of onset Chemical causes: Right after delivery Neisseria gonorrhoeae: Delivery of the baby until 5 days after birth (early onset) Chlamydia trachomatis: 5 days after birth to 2 weeks (late onset – C. trachomatis has a longer incubation period) Complications Untreated cases may develop corneal ulceration, which may perforate, resulting in corneal opacification and staphyloma formation. Cause Non-infectious Chemical irritants such as silver nitrate can cause chemical conjunctivitis, usually lasting 2–4 days. Thus, prophylaxis with a 1% silver nitrate solution is no longer in common use. In most countries, neomycin and chloramphenicol eye drops are used, instead. However, newborns can develop neonatal conjunctivitis due to reactions with chemicals in these common eye drops. Additionally, a blocked tear duct may be another noninfectious cause of neonatal conjunctivitis. Infectious The two most common infectious causes of neonatal conjunctivitis are N. gonorrheae and Chlamydia, typically acquired from the birth canal during delivery. However, other different bacteria and viruses can be the cause, including herpes simplex virus (HSV 2), Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. Ophthalmia neonatorum due to gonococci (N. gonorrhoeae) typically manifests in the first 5 days after birth and is associated with marked bilateral purulent discharge and local inflammation. In contrast, conjunctivitis secondary to infection with C. trachomatis produces conjunctivitis 3 days to 2 weeks after delivery. The discharge is usually more watery in nature (mucopurulent) and