Conjunctivitis is defined as inflammation of the conjunctiva. It is usually caused by infection or allergy. It is often referred to as "pink eye."
Neonatal conjunctivitis occurs in 1.6-12% of newborns. The most common cause is chemical irritation from antimicrobial prophylaxis against bacterial infection,followed by Chlamydia trachomatis infection.Haemophilus influenzae and Streptococcus pneumoniae may also cause infection in newborns.
Rarely, gram-negative organisms such as Escherichia coli, Klebsiella, can cause neonatal conjunctivitis. Neisseria gonorrhoeae is an unusual cause of neonatal conjunctivitis because of the use of ocular prophylaxis.
Herpes simplex can cause neonatal kerato conjunctivitis. However, it is almost always associated with infection of the skin and mucous membranes, or with disseminated disease.
In older infants and children, H influenzae is by far the most common identifiable cause of conjunctivitis, causing 40-50% of episodes. S pneumoniae accounts for 10% of cases, and Moraxella catarrhalis is the third most common cause.
Adenovirus is the most important viral cause of acute conjunctivitis. This organism often causes epidemics of acute conjunctivitis.
In the first day of life, conjunctivitis is usually caused by chemical conjunctivitis secondary to ocular prophylaxis.
Three to 5 days after birth,gonococcal conjunctivitis is the most common cause of conjunctivitis.
After the first week of life and throughout the first month, chlamydia is the most frequent cause of conjunctivitis. Severe cases are associated witha thick mucopurulentdischarge and pseudomembrane formation.
Gonococcal conjunctivitis can present as typical bacterial conjunctivitis, or as a hyperacute conjunctivitis with profuse purulent discharge. There often is severe edema of both lids.
In the older infant and child, both viral and bacterial conjunctivitis may present with an acutely inflamed eye. Typically, there is conjunctival erythema, with occasional lid edema. Exudate often accumulates during the night.
Many patients who have both adenoviral conjunctivitis and pharyngitis also are febrile. The triad of pharyngitis, conjunctivis,and feverhasbeen termed pharyngoconjunctival fever.
In cases of neonatal conjunctivitis, a Gram stain and culture should be obtained to exclude N gonorrhoeae conjunctivitis.
Chlamydia trachomatis antigen detection assays have a sensitivity and specificity of 90%.
Infants and older children. Outside the neonatal period, a Gram stain is usually not needed unless the conjunctivitis lasts longer than 7 days. The presence of vesicles or superficial corneal ulcerations suggests herpetickerato conjunctivitis.
Differential diagnosis of conjunctivitis
Most cases of red eye in children are caused by acute conjunctivitis, allergy, or trauma; however, Kawasaki disease, Lyme disease, leptospirosis, juvenile rheumatoid arthritis, and Stevens-Johnson syndrome may cause conjunctivitis. Glaucoma is a significant cause of a red eye in adults; however, it is rare in children.
Allergic eye disease is characterized by pronounced ocular itching, redness, tearing, and photophobia. This recurrent disease has seasonal exacerbations in the spring, summer, and fall. Children who have allergic conjunctivitis often have other atopic diseases (rhinitis, eczema, asthma) and a positive family history.
: Naphazoline 0.1%(Naphcon),phenyl ephrine (Neo-Synephrine), and oxymetazoline (OcuClear, Visine LR) may be used qid, alone or in combination with ophthalmic antihistamines, such as antazoline (Vasocon-A) or pheniramine maleate (Naph-Con-A).
Topical corticosteroids are helpful, but long-term use is not recommended.