Pinkeye, also known as conjunctivitis, is a commonly-occurring inflammation of the conjunctiva; this thin mucosal membrane lines the inner eyelid and the white part of the eye, providing a protective layer. Normally clear and unnoticeable, when it becomes inflamed through irritation or infection, it causes the redness, itching, tearing, and oozing of pinkeye. You’ve probably heard, since the days of the playground, that it’s highly contagious — and for the most part, that’s true.
The cause of pinkeye affects whether or not it can be spread from one person to another. Pinkeye that’s the result of allergies, with its itchiness and watering, usually clears up once you’re no longer exposed to the allergen, or when you take medication to treat the allergy, and can’t be spread to other people. Similarly, conjunctivitis that is caused by an irritant such as dust, smoke, fumes, chemicals (liquid or in the air), or foreign debris won’t be transmitted to other people — unless they’re exposed to the same substance and it inflames their eye as well.
On the other hand, viral or bacterial infections can also be the source of pinkeye, and both are highly contagious. Viral infections are usually caused by the same viruses responsible for the common cold, and like with a cold, they just need to run their course — while you try not to pass it along to anyone else. Viral infections are contagious for as long as the symptoms (itching, tearing, oozing, redness) are present; these usually begin to clear up within three days to a week. A bacterial infection, often caused by a staph infection, streptococcus pneumonia, or STD bacteria, can be treated with antibiotics. You’ll be contafious as long as symptoms are present, and even with treatment it’s recommended that you wait a full 24 hours after beginning antibiotics to return to work or school.
Good hygiene is essential to avoid spreading — or contracting — pinkeye. Wash your hands regularly and avoid touching your face, eyes, nose, and mouth, especially if you, or someone around you, is infected or has a cold. Don’t share utensils, washcloths, towels, cups, plates, makeup, or other objects, and wipe down common surfaces such as kitchen or bathroom counters.