Pink eye can refer to either conjunctivitis caused by bacteria or that which is caused by a virus. Signs and symptoms typically are red, irritated eyes that are “crusty” and sometimes produce a mucous discharge. Many would argue that true “pink eye” is only the viral kind, while others may use a broader category to include those that are bacterial. The main difference is that viral conjunctivitis is contagious and usually quickly spreads to the other eye. Bacterial conjunctivitis is infection within the eyes, is more common in contact lens wearers, and is rarely seen in non-lens wearers. Viral pink eye is seen on the rise as the incidence of influenza increases, and is more common during flu season. It is also more common in children. Allergic conjunctivitis is really not a true pink eye, and usually involves more itching and occurs frequently during allergy season.
Regardless of what causes it, conjunctivitis is usually treated with a combination steroid/antibiotic eye drop. The bacterial type usually clears up rather quickly. The viral type usually has to run its course, as medicated eye drops decrease the irritation and redness.