Conjunctivitis

Conjunctivitis is inflammation of the conjunctiva, which is the mucous membrane that covers the inside of the eyelid and the sclera of the eye. It is usually transparent but can become erythematous. Conjunctivitis is a clinical diagnosis often made in pediatric patients, commonly referred to by patients and parents as “pink eye.” It is typically benign, self-limited, and easily treated.There is a wide range of presentations, from mild erythema with tearing to copious discharge, diffuse injection, and edema. Infectious causes include bacterial and viral, whereas noninfectious causes include allergic, chemically mediated, and systemic disease. The prevalence of each type of conjunctivitis has not been consistently established. Many other pathologies may present with eye erythema such as blepharitis, foreign body or corneal abrasion, acute angle-closure glaucoma, keratitis, and scleritis, but these are beyond the scope of this In Brief.Viral conjunctivitis is very common in children, most notably due to adenovirus, coxsackie, and enterovirus. It is classically bilateral; however, one eye may appear affected 24 to 48 hours prior to the other. Patients describe a burning or gritty sensation accompanied by irritation, watery discharge, crusting of the eye upon waking, and profuse tearing. Conjunctivitis may be the first and only symptom of a virus, or it may occur in unison with a viral syndrome of fever, upper respiratory infection, and pharyngitis.Viral conjunctivitis is a self-limited but highly contagious process ranging from days to 1 to 2 weeks in duration, as it can mimic the time course of a viral syndrome. It can be easily spread by direct contact with an infected eye or with contaminated objects including hands, towels, clothing, etc. Symptoms tend to be more severe at the onset of the illness. Symptomatic relief can be accomplished with warm or cool compresses and nonantibiotic lubricating agents. Risk of transmission can be limited by avoiding eye rubbing and practicing good hand hygiene until symptoms resolve.There are 2 notable exceptions to typical viral conjunctivitis: epidemic keratoconjunctivitis and herpes simplex virus (HSV). Epidemic keratoconjunctivitis, caused by specific adenovirus subtypes (8, 19, 37), occurs when conjunctivitis extends to the cornea and has the potential to affect long-term visual acuity. Patients present with a severe foreign body sensation in addition to the typical viral conjunctivitis findings, which may affect eyelid opening and/or visual acuity. Corneal infiltrates may be seen on penlight or slit lamp examination. Due to the vision risk, these patients require immediate referral to ophthalmology and possible treatment with topical agents. It is highly contagious until symptoms resolve.HSV conjunctivitis is most known as a cause of neonatal infection (see below); however, it can present at any age, most commonly due to HSV-1. HSV can cause disease in all layers of the eye, presenting as blepharitis, follicular conjunctivitis, keratitis, and keratouveitis. Specifically, HSV keratitis is commonly confused for conjunctivitis and, if not diagnosed and treated, can lead to blindness and/or corneal ulcers and perforation. HSV keratitis can manifest as epithelial or stromal disease and should be considered in any patient presenting with unilateral acute eye pain, photophobia, blurry vision, and watery discharge. Inquiring about a previous history of herpetic lesions in the ocular area, contact lens use, ultraviolet light exposure, and recent topical or systemic corticosteroid use is needed. Evaluation requires polymerase chain reaction testing, viral culture, direct fluorescent antibody testing, and immunohistochemistry and as such may necessitate referral to or consultation with an ophthalmologist. Treatment for HSV keratitis includes topical acyclovir ointment and ganciclovir gel 5 times daily. A total 99% of cases will resolve within 2 weeks of topical treatment. Debridement may be required in resistant cases.Allergic conjunctivitis, seen most commonly in patients with a history of atopy, is due to contact with an allergen triggering a type 1 immunoglobulin E–mediated hypersensitivity reaction. Common allergens include cat dander, pollen, mold, dust mites, cigarette smoke, cosmetic products, and contact lenses. It is characterized by ocular itching, bilateral erythema, and watery or mucoserous “stringy” discharge. The inflammation can also spread, causing eyelid or infraorbital edema.Allergic conjunctivitis can be further divided into acute, seasonal, and perennial subtypes. Acute allergic conjunctivitis develops within minutes of exposure to a known allergen such as cat dander or cigarette smoke and typically resolves within 24 hours. Seasonal allergic conjunctivitis is often due to pollen, develops gradually with seasonal change, and lasts for several months with associated rhinitis. Perennial allergic conjunctivitis is due to indoor allergens (commonly dust mites, mold, and animal dander) and therefore is present year round.Treatment for all subtypes of allergic conjunctivitis includes topical therapies or systemic treatment. The preferred topical agents are daily antihistamine drops. Commercially available vasoconstrictor/antihistamine combination drops can be safe and effective in short duration (<2 weeks); however, longer duration is discouraged due to the risk of rebound hyperemia. Topical ophthalmic steroids can also help relieve acute exacerbations when used under the supervision of an ophthalmologist with appropriate follow-up. Systemic antihistamines are useful in patients who also have rhinitis or pruritus related to allergen exposure.Acute bacterial conjunctivitis is an important cause of conjunctivitis and often the concern of patients and families. It is caused by many pathogens, most commonly Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, and rarely Pseudomonas aeruginosa in patients who wear contact lens or have prolonged hospitalizations. Bacterial conjunctivitis can also be caused by Neisseria gonorrhoeae and Chlamydia trachomatis; however, these are most frequently found in infants and thus discussed at length in the section Neonatal Conjunctivitis below. Bacterial conjunctivitis typically presents unilaterally but may spread to the unaffected eye. It ranges in severity and is characterized by purulent discharge that reappears immediately after wiping. Notably, bacterial conjunctivitis is rarely accompanied by itching or recurrent symptoms. Diagnosis is made clinically.Bacterial conjunctivitis is typically self-limited, with resolution of symptoms within 1 week. Topical antibiotics have been shown to have benefits such as shortening the duration of symptoms if given prior to day 6 of symptoms and reducing the risk of transmission. Topical ophthalmologic antibiotic choices include erythromycin ointment, trimethoprim/polymyxin B drops, or fluoroquinolones in contact lens wearers. Bacterial conjunctivitis is highly contagious until symptoms resolve.There is increasing evidence of resistance to common topical agents used in conjunctivitis. Given most cases will self-resolve, it is the role of the pediatrician to carefully consider the use of topical antibiotics in each patient with likely bacterial conjunctivitis. That said, some daycare centers and schools require at least 24 hours of antibiotics prior to returning, which must be factored into the shared decision-making process.Although neonates can develop any type of conjunctivitis from etiologies mentioned above, there are several unique causes to consider in the first month of life, specifically chemical irritation, C. trachomatis, N. gonorrhoeae, and HSV. Some of the pathogens that lead to neonatal conjunctivitis can cause corneal perforation and ulceration, leading to permanent scarring and ultimately blindness. Therefore, it is crucial to diagnose and treat promptly. Chemical conjunctivitis typically presents in the first 2 days of life due to exposure to a topical agent at birth. This has become less common because it is typically caused by silver nitrate prophylaxis, which is no longer the agent of choice and has been replaced by erythromycin ointment based on Centers for Disease Control and Prevention recommendations.Gonorrheal conjunctivitis presents during days 2 to 4 of life with mucopurulent discharge, significant conjunctival injection, and eyelid edema. Diagnosis is made via nucleic acid amplification testing (NAAT), and it should be treated with a dose of intravenous or intramuscular ceftriaxone and frequent saline rinses. Due to the high risk of penetration into the cornea causing permanent vision loss, infants with gonococcal conjunctivitis must be hospitalized for close observation with ophthalmology consultation because of a high risk of corneal penetration.Chlamydial conjunctivitis is the most common cause of neonatal conjunctivitis due to transmission during birth. It presents during days 5 to 14 of life with watery discharge that can progress to mucopurulent or bloody discharge. Diagnosis is confirmed via NAAT. Approximately 50% of cases are associated with infections at other sites such as pneumonia (which typically presents later around 4 to 12 weeks of age); therefore, it is crucial to treat with systemic erythromycin or azithromycin. A second course of antibiotics is sometimes required due to resistance.Any neonate in whom one suspects chlamydial or gonococcal conjunctivitis should be evaluated for both infections via Gram stain and culture of the conjunctival fluid as well as NAAT.Importantly, application of topical erythromycin to the eyes is recommended for all newborns. There are low-certainty data that suggest prophylaxis is effective at preventing gonococcal infection, but it has not been shown to be effective at preventing chlamydia infection.HSV conjunctivitis, typically caused by HSV-2 via intrauterine or vertical transmission, presents most commonly between days 3 to 15 of life with vesicles on the eyelids, although it can present as late as 6 weeks of age. Diagnosis is confirmed via culture or polymerase chain reaction testing, and if positive, further testing should be done to assess for central nervous system infection. Treatment is needed with acyclovir, and ophthalmology should be consulted due to a high risk of penetration. Test of cure is required, and many infants require long-term suppressive therapy to prevent recurrence, which is typically managed by an infectious disease specialist.Conjunctivitis can be indicative of a systemic disease rather than an isolated issue. Examples include Kawasaki disease, Stevens-Johnson syndrome, inflammatory bowel disease, and systemic lupus erythematosus. All these medical conditions will present with other clinical symptoms that would help distinguish them from the diagnosis of conjunctivitis alone. Several warning signs should prompt immediate referral to ophthalmology, including significant purulent discharge, severe pain or swelling, vision loss, photophobia, severe foreign body sensation that hinders eyelid closing, or poor response to therapy. As discussed, patients with certain etiologies of conjunctivitis, specifically HSV and gonorrheal infection, should be immediately evaluated by ophthalmology, likely as an inpatient, as these patients are admitted for intravenous therapies. It is also appropriate to refer patients with recurrent episodes of conjunctivitis.Comments: One of the challenges I experienced in clinical practice was when infants in the first week of life presented with eye drainage, and I would have to differentiate chlamydia and gonorrheal infections from more benign etiologies. The conundrum was the balance between not wanting to “miss” a serious etiology like gonococcal conjunctivitis when aggressive treatment is needed to prevent ocular perforation with not wanting to worry parents of a young neonate when you hope they are able to experience joy with the birth of their infant. While the common age presentations and some differences in clinical presentations helped, it remains critical to evaluate patients with a high suspicion of these etiologies with Gram stain and sending for appropriate testing of the conjunctival fluid. Later in a child’s life, conjunctivitis can be a fairly common entity, but this In Brief helps differentiate common from more serious etiologies. I sometimes found it challenging to reassure parents that their children with benign viral etiologies required no treatment and would improve over time. In the article under Further Readings, Sebastian and others qualify how “family expectations, antibiotic stewardship, uncertainty of etiologies as viral or bacterial and inconsistent school and day care policies” complicate the decision-making and often serve to have parents expect/request treatment when it may not be needed. Navigating these circumstances reinforces the foundational practices of pediatrics: building trusting relationships with our patients and their parents along with an open dialogue and sharing our respective thought processes.Janet Serwint, MDAssociate Editor, In Brief