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CONJUNCTIVITIS OVERVIEW — Conjunctivitis, also called "pink eye," is defined as an inflammation of the conjunctiva. The conjunctiva is the thin membrane that lines the inner surface of the eyelids and the whites of the eyes (called the sclera) (figure 1). Conjunctivitis can affect children and adults. The most common symptoms of conjunctivitis include a red eye and discharge.
There are many potential causes of conjunctivitis, including bacterial or viral infections, allergies, or a nonspecific condition (eg, a foreign body in the eye). All types of conjunctivitis cause a red eye, although not everyone with a red eye has conjunctivitis.
This topic review discusses the signs and symptoms, evaluation, and treatment of the various types of conjunctivitis.
TYPES OF CONJUNCTIVITIS — There are five main types of conjunctivitis: viral, bacterial, allergic, toxic, and nonspecific. Most cases of infectious conjunctivitis are viral in adults and children; however, bacterial conjunctivitis is more common in children than in adults.
Viral conjunctivitis — Viral conjunctivitis is typically caused by a virus that can also cause the common cold. A person may have symptoms of conjunctivitis alone, or as part of a general cold syndrome, with swollen lymph nodes (glands), fever, a sore throat, and runny nose. (See "Patient education: The common cold in adults (Beyond the Basics)" and "Patient education: The common cold in children (Beyond the Basics)".)
Viral conjunctivitis is highly contagious. It is spread by contact, usually with objects which have come into contact with the infected person's eye secretions. As examples, the virus can be transmitted when an infected person touches their eye and then touches another surface (eg, door handle) or shares an object that has touched their eye (eg, a towel or pillow case).
The most common symptoms of viral conjunctivitis include redness, watery or mucus discharge, and a burning, sandy, or gritty feeling in one eye. Some people have morning crusting followed by watery discharge, perhaps with some scant mucus discharge throughout the day. The second eye usually becomes infected within 24 to 48 hours.
There is no cure for viral conjunctivitis. Recovery can begin within days, although the symptoms frequently get worse for the first three to five days, with gradual improvement over the following one to two weeks for a total course of two to three weeks. Some people experience morning crusting that continues for up to two weeks after the initial symptoms, although the daytime redness, irritation, and tearing should be much improved. (See 'Viral conjunctivitis treatment' below.)
Bacterial conjunctivitis — Bacterial conjunctivitis is highly contagious, often affecting multiple family members or children within a classroom. Bacterial conjunctivitis is spread by contact, usually with objects which have come into contact with the infected person's eye secretions. As examples, the bacterium can be transmitted when an infected person touches their eye and then touches another surface (eg, door handle) or shares an object that has touched their eye (eg, a towel or pillow case).
The most common symptoms of bacterial conjunctivitis include redness and thick discharge from one eye, although both eyes can become infected. The discharge may be yellow, white, or green, and it usually continues to drain throughout the day. The affected eye often is "stuck shut" in the morning.
Most types of bacterial conjunctivitis resolve quickly and cause no permanent damage when treated with antibiotic eye drops or ointment. (See 'Bacterial conjunctivitis treatment' below.)
Allergic conjunctivitis — Allergic conjunctivitis is caused by airborne allergens that come in contact with the eye. Symptoms (most commonly redness, watery discharge, and itching of both eyes) may be sudden in onset (acute), seasonal, or present year-round (perennial), depending upon the allergen. Allergic conjunctivitis is discussed in a separate topic. (See "Patient education: Allergic conjunctivitis (Beyond the Basics)".)
Toxic conjunctivitis — Toxic conjunctivitis (also called toxic keratoconjunctivitis) is a chronic inflammation of the surface of the eye from an offending agent, usually a preservative or a medication. Toxic conjunctivitis is discussed in a separate topic. (See "Toxic conjunctivitis".)
Nonspecific conjunctivitis — It is possible to develop a red eye and discharge that is not caused by an infection or allergy or toxicity. The most common causes include one of the following:
●People with a dry eye may have chronic or intermittent redness or discharge.
●A person whose eyes are irrigated after a chemical splash may have redness and discharge.
●A person with a foreign body (eg, dust, eyelash) in the eye may have redness and discharge for 12 to 24 hours after the object is removed.
All of these problems generally improve spontaneously within 24 hours.
CONJUNCTIVITIS DIAGNOSIS — The diagnosis of conjunctivitis most often requires an examination by a health care provider or eye care specialist because many conditions can cause eye redness.
The health care provider may ask the following questions:
●When did the eye problem begin? Has anyone else in the house had a similar problem?
●Is there discharge from the eye continuously? Is the discharge watery, thin, and mucus-like, or thick and sticky?
●Are there any non-eye symptoms (eg, coughing, fever, sore throat, nasal congestion, sneezing)?
●Are the eyes extremely itchy or is there a history of seasonal allergies?
Referral to eye care specialist — People with the following signs and symptoms may have a more serious problem and should be evaluated immediately by an eye specialist (ophthalmologist or optometrist).
●Difficulty seeing clearly
●Difficulty keeping the eye open or sensitivity to light
●Severe headaches with nausea
●Recent trauma to the eye
●Use of contact lenses
CONJUNCTIVITIS TREATMENT — The treatment of conjunctivitis depends upon the cause. For this reason, it is important to have the correct diagnosis before treatment begins.
Viral conjunctivitis treatment — A topical antihistamine/decongestant eye drop may help to relieve the irritation of viral conjunctivitis. These drops are available without a prescription in most pharmacies. However, particular care must be taken to avoid spreading viral infections from one eye to the other. Apply drops only to affected eye and wash hands thoroughly after application. Similar to cold medicines, this treatment may reduce the symptoms but does not shorten the course of the infection. Another option is to use warm or cool compresses, as needed.
The irritation and discharge may get worse for three to five days before getting better, and symptoms can persist for two to three weeks.
Bacterial conjunctivitis treatment — Bacterial conjunctivitis is usually treated with an antibiotic eye drop or ointment. When started early, treatment helps to shorten the duration of symptoms, although most cases do resolve spontaneously if no treatment is used.
Adults — Adults are usually treated with an antibiotic eye drop or ointment for five to seven days. Redness, irritation, and eye discharge should begin to improve within 24 to 48 hours. If there is no improvement or if the condition worsens within this time, the person should be evaluated by an ophthalmologist.
Contact lens wearers — People who wear contact lenses should be evaluated by a health care provider before treatment begins; this is to confirm the diagnosis of conjunctivitis and to be sure that another, more serious condition related to contact lens use (an infection of the cornea), is not present.
People who wear contact lenses should avoid wearing the lenses during the first 24 hours of treatment, or until the eye is no longer red. The contact case should be thrown away and the contacts disinfected overnight or replaced (if disposable).
Children — Children with bacterial conjunctivitis may be treated with antibiotic eye drops or ointment. Ointment is generally preferred for young children and those who have difficulty applying eye drops. Ointment should be applied inside the lower eyelid. Even if the ointment is not applied directly inside the eyelid, it is usually effective because it sticks to the lid and is spread with blinking. Vision may be blurred for up to 20 minutes after use of ointment.
Return to work/school — The safest approach to avoid spreading viral and bacterial conjunctivitis to others is to stay home until there is no longer any discharge from the eye(s). However, this is not practical for most students and for those who work outside the home. Most daycare centers and schools require that students receive 24 hours of antibiotic eye drops or ointment before returning to school. This treatment helps to prevent the spread of bacterial conjunctivitis, but is not necessary or helpful for children with viral conjunctivitis.
Viral conjunctivitis is similar to a cold because it spreads easily between people. Younger children, who may not remember to wash their hands or avoid touching their eyes, should probably not attend school until the discharge has resolved. Older students or adults may choose to attend school/work, although they should limit close contact with others.
In addition, adults who have contact with the very old, the very young, or people with a weakened immune system should avoid these susceptible individuals.
Nonspecific conjunctivitis treatment — The conjunctiva heals quickly after it is injured, and nonspecific conjunctivitis usually resolves within a few days without any treatment. However, the eye may feel better faster when it is treated with a lubricant, such as drops or ointments. These products are available without a prescription in most pharmacies. Preservative-free preparations are more expensive and are necessary only for people with a severe case of dry eye and those who are allergic to preservatives.
Preservative-free lubricant drops can be used as often as hourly with no side effects. Regular drops with preservatives should only be used up to six times per day. The ointment provides longer lasting relief but blurs vision temporarily. For this reason, some people use ointment only at bedtime. It may be worthwhile to switch brands if one brand of drop or ointment is irritating, since each preparation contains different active and inactive ingredients and preservatives.
Antibiotic or steroid eye drops/ointments are not recommended unless there is a specific reason they are needed (eg, a bacterial infection or inflammatory condition). Using these treatments when they are not needed can lead to serious complications. If the symptoms of conjunctivitis do not improve within two weeks, an examination with an ophthalmologist may be recommended.
CONJUNCTIVITIS PREVENTION — Bacterial and viral conjunctivitis are both highly contagious and spread by direct contact with secretions or contact with contaminated objects. Simple hygiene measures can help minimize transmission to others:
●Adults or children with bacterial or viral conjunctivitis should not share handkerchiefs, tissues, towels, cosmetics, or bedsheets/pillows with uninfected family or friends.
●Hand washing is an essential and highly effective way to prevent the spread of infection. Hands should be wet with water and plain soap and rubbed together for 15 to 30 seconds. It is not necessary to use antibacterial hand soap. Teach children to wash their hands before and after eating and after touching the eyes, coughing, or sneezing.
●Alcohol-based hand rubs are a good alternative for disinfecting hands if a sink is not available. Hand rubs should be spread over the entire surface of hands, fingers, and wrists until dry, and they may be used several times. These rubs can be used repeatedly without skin irritation or loss of effectiveness.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient education: Conjunctivitis (pink eye) (The Basics)
Patient education: Stye (hordeolum) (The Basics)
Patient education: Blocked tear duct (The Basics)
Patient education: Reactive arthritis (The Basics)
Patient education: Photokeratitis (arc eye) (The Basics)
Patient education: Pterygium (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
The following organizations also provide reliable health information.
●National Library of Medicine
●American Academy of Allergy, Asthma, and Immunology