The three main types of conjunctivitis are:. Bacterial conjunctivitis is more common in children than it is in adults. Bacterial conjunctivitis usually causes substantial amounts of thick eye discharge that may be white, yellow, or green. It is usually more difficult to distinguish between allergic conjunctivitis and viral conjunctivitis because the discharge can be virtually the same. The main distinguishing feature between these two conditions is that allergic conjunctivitis usually causes itchy eyes, which may be felt as grittiness or burning.
Allergic conjunctivitis is an inflammatory process, which means the immune system reacts or overreacts to allergens.
These allergens contact the eye through the air or through touch and, once in contact with the eye, they provoke an immune response. Common allergens include tree pollen, grass pollen, ragweed pollen, and pet dander. Allergic conjunctivitis causes redness in one or usually both eyes, watery discharge or tearing, and itchiness.
Unfortunately, people tend to rub itchy eyes, which makes the reaction worse. The eyelid may be swollen and the redness may extend beyond the eye itself. The immune system recognises the allergen at every exposure. Therefore, people who are allergic to tree pollen, for example, can usually expect to have allergic conjunctivitis seasonally, when plant pollen levels are high.
A person who is allergic to cat dander may notice an acute conjunctivitis that occurs after petting a cat and then touching his or her own eye. Identifying the source of the allergy can be helpful since the person afflicted with that allergy can learn to avoid or reduce exposure to the allergen. Allergen avoidance is a key part of managing allergic conjunctivitis; however, completely avoiding some airborne allergens is virtually impossible. Staying indoors and using air conditioning can help reduce airborne allergen exposure.
For people allergic to dust mites, frequent cleaning, linen and towel changes, and trading carpets for hardwood or tile floors can help reduce the burden of allergens. Once allergic conjunctivitis has occurred, the patient should not rub their eyes even if they itch because this intensifies the allergic reaction and inflammation. Cool compresses may be helpful for relieving symptoms and swelling. Artificial tears used throughout the day can dilute allergens on the surface of the eye and reduce the reaction.
Oral antihistamines may be helpful in treating mild cases of allergic conjunctivitis. Various eye drops can be used to reduce symptoms of allergic conjunctivitis, these are usually used in patients with severe symptoms.
These eye drops include antihistamines, mast cell stabilizers, nonsteroidal anti-inflammatories, and glucocorticoids. Bacterial conjunctivitis is distinguished from other forms of conjunctivitis by thick secretions and purulent pus-containing discharge from the eye.
The secretions come so quickly that they may return moments after wiping the eye. Unlike allergic conjunctivitis, bacterial conjunctivitis does not usually cause itchiness.
Bacterial conjunctivitis is caused by Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Bacterial conjunctivitis is extremely contagious and is transmitted through direct contact to someone's eye with infectious material. In other words, someone with bacterial conjunctivitis may spread the infection by contaminating surfaces that others then touch or, less likely, infecting others through direct contact.
There is no universally effective method to prevent the spread of infectious conjunctivitis. Infected individuals should not share materials that contact the face such as towels, cosmetics, linens, or silverware. Others require antibacterial eye drops for least 24 hours before returning. While these efforts may be helpful in reducing the spread of the infection, transmission may still occur. Moreover, antibacterial eye drops will do nothing to stop viral conjunctivitis, which is also highly contagious.
Fortunately, most cases of bacterial conjunctivitis are self-limited and resolve within a few days to weeks even without the use of antibiotics. Signs and symptoms of bacterial conjunctivitis overlap with other causes of conjunctivitis, including viral and allergic conjunctivitis, which can make diagnosis difficult. Typical signs and symptoms include:.
Contact lens wearers with bacterial conjunctivitis are at higher risk of bacterial keratitis. They should be asked to remove their contact lenses, treated with topical antibiotics, and promptly evaluated by an ophthalmologist. Learn more about trachoma and other hygiene-related diseases.
Scanning electron micrograph of an Ambrosia trifida plant, more commonly known as ragweed. Allergic conjunctivitis is common in people who have other signs of allergic disease, such as hay fever, asthma, and eczema.
Skip directly to site content Skip directly to page options Skip directly to A-Z link. Conjunctivitis Pink Eye. Section Navigation. Facebook Twitter LinkedIn Syndicate. For Clinicians. Minus Related Pages. The first step is to remove or avoid the irritant, if possible.
Cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, nonsteroidal anti-inflammatory medications and antihistamines may be prescribed. People with persistent allergic conjunctivitis may also require topical steroid eye drops. Oral antihistamines may also be prescribed. This type of conjunctivitis is usually treated with antibiotic eye drops or ointments. Bacterial conjunctivitis may improve after three or four days of treatment, but patients need to take the entire course of antibiotics to prevent a recurrence.
Viral conjunctivitis. No drops or ointments can treat viral conjunctivitis. Antibiotics will not cure a viral infection. Like a common cold, the virus has to run its course, which may take up to two or three weeks. Symptoms can often be relieved with cool compresses and artificial tear solutions. For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation. However, these drops will not shorten the infection. Careful flushing of the eyes with saline is a standard treatment for chemical conjunctivitis.
People with chemical conjunctivitis also may need to use topical steroids. Severe chemical injuries, particularly alkali burns, are medical emergencies and can lead to scarring, damage to the eye or the sight, or even loss of the eye. If a chemical spills in your eye, flush the eye for several minutes with a lot of water before seeing your medical provider.
Contact lens wearers may need to temporarily stop wearing their lenses while the condition is active. If conjunctivitis is due to wearing contact lenses, a doctor of optometry may recommend switching to a different type of contact lens or disinfection solution. A doctor of optometry might need to change the contact lens prescription to a lens that is replaced more frequently. This can help prevent conjunctivitis from recurring.
Practicing good hygiene is the best way to control the spread of conjunctivitis. Once an infection has been diagnosed, follow these steps:. Soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses to your affected eye or eyes. To make a compress, soak a clean cloth in warm water and wring it out before applying it gently to your closed eyelids. For allergic conjunctivitis, avoid rubbing the eyes. Instead of warm compresses, use cool compresses to soothe your eyes.
Over-the-counter eye drops might also help. Antihistamine eye drops can alleviate the symptoms, and lubricating eye drops can rinse the allergen off the surface of the eye. See your doctor of optometry if you think you have conjunctivitis.
He or she can diagnose the cause and prescribe the proper treatment. With so many causes, there is no one preventive measure. Early diagnosis and treatment will help prevent the condition from becoming worse. Avoiding allergy triggers as much as possible also helps.
Frequent hand washing and keeping hands away from eyes also can make a difference, even when no problems are present.
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