Pink eye, also commonly known as conjunctivitis, occurs when the surface of your eyeball and inner lining of your eyelid become inflamed.
Bacteria, viruses, allergies, irritants and other underlying infectious or noninfectious diseases can cause pink eye.
Although conjunctivitis can occur in adults, it more commonly affects children.
Pink eye is most commonly caused by a viral infection but can also be caused by a bacterial infection.
Staphylococci, streptococci, gonococci or chlamydia are common bacterial causes of conjunctivitis.
Viral conjunctivitis can be caused by a variety of viruses such as adenoviruses.
The virus or bacteria from an infected person’s eye can spread through contact with skin, eyewear, cosmetics and cosmetic brushes, linens or towels. Pink eye can even spread from one eye to the other in the same person.
In cases when an infection is not present, pink eye can be contributed to:
Allergic conjunctivitis is caused by the body’s reaction to allergens such as pollen from trees, plants, grasses, weeds, medicine, cosmetics or molds. Allergic conjunctivitis is not contagious.
Risk of viral or bacterial pink eye can be reduced with proper hygiene, disinfection and by eliminating contact with others who have the condition.
Risk factors for non-infectious pink eye include:
• Dry eyes — having naturally dry eyes or not protecting the eyes in windy or dry environments can contribute to pink eye.
• Allergies — those who have pollen, mold or other allergies are likely to develop pink eye as a response to exposure of allergens.
• Use of contact lenses
Symptoms of pink eye vary depending on the cause of the irritation.
Symptoms of viral pink eye include:
• Watery discharge that resemble tears
• Runny nose
• Sinus congestion
• Puffy or swollen eyelids
• Sensitivity to light
Viral conjunctivitis is highly contagious and will remain transmittable and can cause symptoms for as long as two weeks.
Symptoms of bacterial pink eye include:
• Red, itchy or burning eye
• Thick green or yellow eye discharge that turns crusty overnight
• Swollen lymph nodes above the jaw (in front of ears)
Symptoms of allergic conjunctivitis are most common during allergy season in a patient who has other allergic rhinitis symptoms such as hay fever, asthma or eczema.