Pink eye | Conjunctivitis
Pink eye (conjunctivitis) is an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and covers the white part of your eyeball. When small blood vessels in the conjunctiva become inflamed, they’re more visible. This is what causes the whites of your eyes to appear reddish or pink. It may be acute or chronic. Most cases are due to viral or bacterial (including gonococcal and chlamydial) infection.
Other causes include keratoconjunctivitis sicca, allergy, chemical irritants, and deliberate self-harm. The mode of transmission of infectious conjunctivitis is usually direct contact via fingers, towels, handkerchiefs, etc, to the fellow eye or to other persons. It may be through contaminated eye drops. Conjunctivitis must be differentiated from acute uveitis, acute glaucoma, and corneal disorders.
Symptoms of conjunctivitis (pink eye) can include
- Pink or red color in the white of the eye(s)
- Swelling of the conjunctiva (the thin layer that lines the white part of the eye and the inside of the eyelid) and/or eyelids
- Increased tear production
- Feeling like a foreign body is in the eye(s) or an urge to rub the eye(s)
- Itching, irritation, and/or burning
- Discharge (pus or mucus)
- Crusting of eyelids or lashes, especially in the morning
- Contact lenses that feel uncomfortable and/or do not stay in place on the eye
Depending on the cause, other symptoms may occur.
Adenovirus is the most common cause of viral conjunctivitis. There is usually bilateral disease with copious watery discharge, often with marked foreign body sensation, and a follicular conjunctivitis. Infection spreads easily, sometimes in eye clinics and contaminated swimming pools. Epidemic keratoconjunctivitis, which may result in visual loss due to corneal subepithelial infiltrates, is usually caused by adenovirus types 8, 19, and 37. The disease lasts at least 2 weeks. Infection with adenovirus types 3, 4, 7, and 11 is typically associated with pharyngitis, fever, malaise, and preauricular adenopathy (pharyngoconjunctival fever).
The disease usually lasts 10 days. Viral conjunctivitis may also be due to herpes simplex virus (HSV), when it is usually unilateral and may be associated with lid vesicles, and enterovirus 70 or coxsackievirus A24 that characteristically cause acute hemorrhagic conjunctivitis.
Except for HSV infection for which treatment with topical (eg, ganciclovir 0.15% gel) and/or systemic (eg, oral acyclovir) antivirals is recommended, there is no specific treatment. Cold compresses reduce discomfort and topical sulfonamides (or oral antibiotics) can be prescribed to prevent secondary bacterial infection. The value of weak topical corticosteroids or topical cyclosporine for corneal infiltrates due to adenoviral infection is uncertain.
The organisms isolated most commonly in bacterial conjunctivitis are staphylococci, including methicillin-resistant S aureus (MRSA); streptococci, particularly S pneumoniae; Haemophilus species; Pseudomonas; and Moraxella. All may produce a copious purulent discharge. There is no blurring of vision and only mild discomfort. In severe (hyperpurulent) cases, examination of stained conjunctival scrapings and cultures is recommended, particularly to identify gonococcal infection that requires emergent treatment.
The disease is usually self-limited, lasting about 10–14 days if untreated. A topical antibiotic will usually clear the infection in 2–3 days. Except in special circumstances, the use of topical fluoroquinolones is rarely justified for treatment of a generally self-limiting, benign infection.
Gonococcal conjunctivitis, usually acquired through contact with infected genital secretions, typically causes copious purulent discharge. It is an ophthalmologic emergency because corneal involvement may rapidly lead to perforation. The diagnosis should be confirmed by stained smear and culture of the discharge. Systemic treatment is required. A single 1-g dose of intramuscular ceftriaxone is usually adequate. (Fluoroquinolone resistance is common.) Topical antibiotics such as erythromycin and bacitracin may be added. Other sexually transmitted diseases, including chlamydiosis, syphilis, and HIV infection, should be considered. Routine treatment for chlamydial infection is recommended.
Trachoma is the most common infectious cause of blindness worldwide, with approximately 40 million people affected and 1.2 million blind. Recurrent episodes of infection in childhood manifest as bilateral follicular conjunctivitis, epithelial keratitis, and corneal vascularization (pannus). Scarring (cicatrization) of the tarsal conjunctiva leads to entropion and trichiasis in adulthood with secondary central corneal scarring.
Immunologic tests or polymerase chain reaction on conjunctival samples will confirm the diagnosis but treatment should be started on the basis of clinical findings. A single 1-g dose of oral azithromycin is the preferred drug for mass treatment campaigns, but improvements in hygiene and living conditions probably have contributed more to the marked reduction in the prevalence of trachoma during the past 25 years. Local treatment is not necessary. Surgical treatment includes correction of lid deformities and corneal transplantation.
The eye becomes infected after contact with infected genital secretions. The disease starts with acute redness, discharge, and irritation. The eye findings consist of follicular conjunctivitis with mild keratitis. A non-tender preauricular lymph node can often be palpated. Healing usually leaves no sequelae. Diagnosis can be rapidly confirmed by immunologic tests or polymerase chain reaction on conjunctival samples. Treatment is with a single dose of azithromycin, 1 g orally. All cases should be assessed for genital tract infection and other sexually transmitted diseases.
Viral and bacterial conjunctivitis (pink eye) are very contagious. They can spread easily from person to person. You can greatly reduce the risk of getting conjunctivitis or spreading it to someone else by following some simple steps for good hygiene.
If You Have Conjunctivitis
If you have conjunctivitis, you can help limit its spread to other people by following these steps:
- Wash your hands often with soap and warm water for at least 20 seconds. Wash them especially well before and after cleaning, or applying eye drops or ointment to, your infected eye. If soap and water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol to clean hands.
- Avoid touching or rubbing your eyes. This can worsen the condition or spread it to your other eye.
- With clean hands, wash any discharge from around your eye(s) several times a day using a clean, wet washcloth or fresh cotton ball. Throw away cotton balls after use, and wash used washcloths with hot water and detergent, then wash your hands again with soap and warm water.
- Do not use the same eye drop dispenser/bottle for your infected and non-infected eyes.
- Wash pillowcases, sheets, washcloths, and towels often in hot water and detergent; wash your hands after handling such items.
- Stop wearing contact lenses until your eye doctor says it’s okay to start wearing them again.
- Clean eyeglasses, being careful not to contaminate items (like hand towels) that might be shared by other people.
- Clean, store, and replace your contact lenses as instructed by your eye doctor.
- Do not share personal items, such as pillows, washcloths, towels, eye drops, eye or face makeup, makeup brushes, contact lenses, contact lens storage cases, or eyeglasses.
- Do not use swimming pools.
If You Are Around Someone with Conjunctivitis
If you are around someone with conjunctivitis, you can reduce your risk of infection by following these steps:
- Wash your hands often with soap and warm water for at least 20 seconds. If soap and warm water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol to clean hands.
- Wash your hands after contact with an infected person or items he or she uses; for example, wash your hands after applying eye drops or ointment to an infected person’s eye(s) or after putting their bed linens in the washing machine.
- Avoid touching your eyes with unwashed hands.
- Do not share items used by an infected person; for example, do not share pillows, washcloths, towels, eye drops, eye or face makeup, makeup brushes, contact lenses, contact lens storage cases, or eyeglasses.