conjunctivitis

Conjunctivitis, commonly called pink eye, is inflammation of the conjunctiva, the thin membrane that lines the inside of the eyelids and covers the white of the eye. It can affect one or both eyes and may be caused by infection, allergy, or irritation.

Symptoms typically include redness, itching, and a gritty or burning sensation. Tearing and a discharge that can be watery or mucopurulent are common, and the eyelids may be swollen. The discharge may cause the eyes to stick shut upon waking. Infectious forms are easily spread through eye secretions and contaminated objects or hands.

Causes fall into several categories. Bacterial and viral infections are common, with viruses often associated with upper respiratory symptoms. Allergic conjunctivitis occurs in people with allergies and tends to affect both eyes, with prominent itching and a watery or slightly stringy discharge. Irritant conjunctivitis results from exposure to substances such as smoke, chlorine, or pollutants.

Diagnosis is usually clinical, based on history and eye examination. More severe or uncertain cases may require laboratory tests or cultures to identify the cause and rule out other conditions, such as keratitis or uveitis.

Treatment depends on the cause. Bacterial conjunctivitis is typically treated with topical antibiotics. Viral conjunctivitis usually resolves without specific antiviral therapy, with supportive care such as lubrication and cold compresses. Allergic conjunctivitis is managed with antihistamine or anti-inflammatory eye drops and by avoiding allergens. Irritant conjunctivitis improves after removing the irritant. Prevention focuses on hand hygiene, avoiding eye rubbing, not sharing towels or makeup, proper contact lens hygiene, and staying home from school or work when discharge is present. Most cases improve within one to two weeks. Complications are rare but can include keratitis, especially in contact lens users or those with compromised immunity.