Conjunctivitis is inflammation of the outermost layer of the eye and is also known as pink eye. The white region of the eye is lined by a transparent, mucous membrane called the conjunctiva. It is inflammation of this conjunctiva, marked by redness and itching that is seen in conjunctivitis. Overall conjunctivitis is a common eye problem that typically occurs due to a viral infection, which is highly contagious. However, there are other infectious and non-infectious causes of conjunctivitis.
As the name suggests, a pink color or redness of the eye is the most pronounced sign of conjunctivitis. It is usually accompanied by swelling, itching of the eyes and a mucus discharge. Other symptoms may vary depending on whether the causal factors are viral or bacterial infection or due to an allergy.
Other symptoms of viral conjunctivitis include:
- Sore throat and difficult breathing
- Burning sensation in the eye and eyelids
- Swollen areas in front of the ears
- Clear and slightly thick, white-colored drainage
Signs of bacterial conjunctivitis include:
- Drainage of yellow colored fluid from the eye that causes the eyelashes to stick together
- Mild to intense pain
- Swelling of the upper eyelid that makes the lid heavy and drooping
Initially the sign appears in one eye that eventually spreads to the other eye. Depending on the causative factors, conjunctivitis may resolve on its own within a week or two.
Conjunctivitis may be due to various causes. Infections are the main cause of conjunctivitis. Viral infections are more common and often leads to outbreaks especially among children in school and day care centers. Bacterial infections are less common but often more severe. Both viral and bacterial conjunctivitis are highly contagious. The infection can spread through direct or indirect contact with the eye secretions of the infected person.
Conjunctivitis may also appear as a heightened immune response towards allergens like pollens. Contrary to those caused by infections, allergic conjunctivitis usually appears in both the eyes at the same time. The cells present under the lining of the eye produces histamine, a chemical that produces local inflammation and swelling. Characteristically, allergic conjunctivitis accompanies repeated sneezing with watery discharge from the eye and a runny nose.
Irritation of the mucosal membrane of the eyes by certain chemicals may also lead to conjunctivitis. These chemicals may be in the liquid, solid or gas form and occurs when it comes into direct contact with the eye. In such cases, the redness of eyes tends to reduce upon splashing water and cleaning the affected eyes.
People wearing contact lenses are more likely to harbor eye infections that may progress into conjunctivitis. Contact lenses that are not fitting appropriately or are torn can also injure the conjunctiva.
Viral conjunctivitis often resolves on its own and does not require any specific treatment. Some forms, like recurrent viral conjunctivitis caused by the herpes simplex virus may require antiviral medication. Antibiotic eye drops and ointments are prescribed for bacterial conjunctivitis. Antihistamines offer relief in case of allergic conjunctivitis. Avoiding the allergy-causing substances help prevent the allergy-related redness of eyes. Corticosteroid drops may be needed to reduce severe inflammation and pain in all types of conjunctivitis.