What Are the Causes of Pinkeye?

Pinkeye, or conjunctivitis, is the swelling of the membrane that covers the white part of the eye. The conjunctiva is a small, thin membranous layer that covers the exposed areas of the eye protecting them from dirt and the elements. There are many causes for conjunctiva swelling, but the term "pinkeye" is most often used when referring to those cases caused by infection from bacteria or viruses. Pinkeye is extremely contagious, and is spread through coughing and sneezing, and direct contact with someone who has pinkeye.

Viral Infections

• Viruses that cause pinkeye are usually associated with accompanying cold or flu-like symptoms. The main difference between viral and bacterial conjunctivitis is the discharge. Viral infections are normally clear and watery while bacterial infections have a thick green or yellow mucus excretion. Viral pinkeye infections may also be accompanied by sinusitis symptoms and swollen eyelids.

Bacterial Infections

• There are three main sources of bacterial pinkeye: staphylococci, pneumococci and streptococci. Bacterial infections are the cause of the crusty discharge patients experience during sleep.

Chlamydia and Gonorrhea

• If a mother is infected with chlamydia or gonorrhea, her baby may be born with chlamydial or gonococcal pinkeye. In these cases, antibiotic treatment should begin immediately. Pinkeye can also be sexually transmitted.

Allergic Reactions

• Allergic reactions can cause the tearing, redness and swelling associated with allergic conjunctivitis. Pollen, dust, mold and animal dander lead to inflammation of the conjunctiva in allergy patients.

Irritants

• Irritants such as cigarette smoke, aerosols, household cleaners and industrial waste products can cause the redness, swelling and itchiness associated with pinkeye. The eye should be washed out with water to remove the chemicals or other irritants.

Disease

• Chronic diseases can lead to pinkeye symptoms. Chronic cases of pinkeye can be a symptom of an undiagnosed disease. Autoimmune disorders such as rheumatoid arthritis and systemic lupus bring out the symptoms of pinkeye. Conjunctivitis has also been associated with diseases common in children, such as Kawasaki's disease, colitis and Crohn's disease.