Conjunctivitis, commonly known as pink eye, is an inflammation of the conjunctiva, the thin, transparent membrane that covers the white part of the eyeball and the inner surface of the eyelids. This irritation causes the small blood vessels in the conjunctiva to become swollen, making the eye appear reddish or pink. While most cases are acute and short-lived, some forms of this condition can become chronic, lasting for months. Understanding the typical duration of common cases versus chronic types helps clarify when to seek further care.
How Long Pink Eye Usually Lasts
The majority of conjunctivitis cases are acute and resolve quickly, typically within one to four weeks, depending on the cause. Viral conjunctivitis, often caused by adenoviruses, is highly contagious and usually follows a self-limited course. Symptoms usually peak around three to five days and resolve completely within seven to fourteen days, though some strains can take up to four weeks to clear.
Bacterial conjunctivitis is characterized by a thick, sticky discharge and also tends to be self-limiting, often clearing up within one to two weeks without intervention. A healthcare provider may prescribe topical antibiotic drops or ointments, which can significantly shorten the duration of symptoms. With treatment, patients often see improvement within 24 hours and full resolution within a few days. When a case lasts longer than three to four weeks, it is classified as chronic conjunctivitis, suggesting a different underlying cause.
Types of Conjunctivitis That Linger
When pink eye symptoms persist for weeks or months, the cause is generally chronic inflammation rather than a common acute infection. One frequent cause is allergic conjunctivitis, which is not contagious. This condition is an immune response triggered by environmental allergens such as pollen, pet dander, or mold spores. The inflammation and intense itching will continue until the person is removed from the specific allergen causing the reaction.
Another form that can linger is toxic or irritant conjunctivitis, resulting from exposure to chemicals, smoke, or certain eye drops and contact lens solutions. This persistent irritation causes chronic redness and discomfort. Symptoms will only subside once the offending irritant is identified and removed from the individual’s environment.
In less common cases, a prolonged infection may be caused by specific pathogens requiring systemic treatment. Inclusion conjunctivitis, caused by Chlamydia trachomatis, is a sexually transmitted infection that causes chronic, low-grade inflammation if undiagnosed. This form requires oral antibiotics, as topical drops alone are insufficient. Persistent adenoviral strains can also cause chronic inflammation, leaving opaque spots on the cornea known as subepithelial infiltrates, which may cause visual disturbances for several months.
Warning Signs Requiring Medical Attention
While typical pink eye usually resolves on its own, certain symptoms indicate a more serious or sight-threatening condition. Any development of severe or worsening eye pain should prompt an immediate medical evaluation, as pain suggests deeper tissue involvement beyond the conjunctiva. A sudden change in vision, such as blurriness or decreased sharpness, also requires urgent attention.
These visual changes signal that the inflammation may have spread to the cornea, leading to keratitis. Extreme sensitivity to light (photophobia) is frequently associated with corneal involvement and should be evaluated promptly. The appearance of white spots or lesions on the clear cornea is a direct sign of a serious inflammatory or infectious process.
If eye symptoms are accompanied by systemic signs like a fever, severe headache, or significant swelling of the lymph nodes, it may indicate a robust systemic infection. If symptoms fail to improve after seven to ten days of home care or initial treatment, a specialist should perform a differential diagnosis to identify the correct chronic cause.