Pink eye, or conjunctivitis, is the inflammation of the conjunctiva, a clear membrane covering the white part of the eye and lining the eyelid. This common condition can affect one or both eyes, causing irritation and visible changes. It can be caused by viral or bacterial infections, allergic reactions, or exposure to irritants.
Understanding Pink Eye Onset
The onset of pink eye symptoms varies significantly depending on its underlying cause. This incubation period, or time from exposure to symptom onset, helps distinguish between different types of conjunctivitis.
Viral conjunctivitis, the most common type, often accompanies colds and respiratory infections. Symptoms usually appear within 1 to 3 days after exposure, but can take up to a week. Adenovirus is a frequent cause, and the virus can spread from the respiratory system to the eyes, for instance, through forceful nose blowing.
Bacterial conjunctivitis often has a more rapid onset than viral forms. Symptoms typically develop within 24 to 72 hours after bacterial exposure. Common bacteria causing this infection include Staphylococcus aureus or Streptococcus pneumoniae, which can originate from a person’s own skin or respiratory system.
Allergic conjunctivitis is not an infection and lacks an incubation period. Symptoms like redness, itching, and watering appear almost immediately upon contact with allergens such as pollen, dust mites, or pet dander. Irritant or chemical conjunctivitis, caused by substances like smoke or harsh chemicals, also results in immediate symptoms.
Recognizing Common Symptoms
Most forms of pink eye share several common signs and sensations. A noticeable redness or pinkish tint in one or both eyes is a primary indicator. Individuals often report an itchy or irritated feeling, along with a gritty sensation, as if something is in the eye.
Eye discharge is another common symptom, varying in consistency and color by type. Viral or allergic conjunctivitis typically produces a watery discharge. Bacterial infections often result in a thick, yellow, white, or green discharge that can crust over the eyelids, especially overnight. Increased tear production and sensitivity to light (photophobia) can also occur. Eyelid swelling is sometimes present.
Contagious Period and Transmission
Pink eye’s contagiousness depends on its cause. Infectious forms, specifically viral and bacterial conjunctivitis, spread through direct or indirect contact with eye secretions from an infected person. This can occur by touching contaminated surfaces and then one’s own eyes, or through close personal contact.
Viral conjunctivitis is highly contagious, often starting before symptoms appear, and remains so as long as symptoms are present, typically for 10 to 14 days. Bacterial conjunctivitis is contagious as long as there is eye discharge. If antibiotics are prescribed, contagiousness usually ends within 24 to 48 hours after starting treatment; without antibiotics, it can remain contagious for about a week. Allergic and irritant conjunctivitis are not contagious because they are not caused by an infection.
When to Seek Care and Prevention
Seek medical attention if symptoms are severe, include significant eye pain, or affect vision. Consult a healthcare provider if symptoms worsen, show no improvement after a few days, or if there is intense eye redness or excessive discharge. Newborns with any signs of pink eye require immediate medical evaluation due to the risk of serious complications.
Preventive measures focus on hygiene to limit the spread of infectious types. Wash hands frequently with soap and water for at least 20 seconds, especially after contact with an infected person or their belongings. Avoid touching or rubbing eyes, sharing personal eye items like towels, makeup, or contact lenses, and change pillowcases regularly. Contact lens wearers should clean lenses properly and stop wearing them if symptoms occur.