Conjunctivitis: Videos & Practice Problems

Conjunctivitis, commonly known as pink eye, is primarily caused by infections that lead to inflammation of the conjunctiva, the thin mucous membrane covering the front of the eye and lining the inside of the eyelids. The two main causes are viral and bacterial infections. Viral conjunctivitis is most often caused by adenoviruses, which can also cause respiratory infections. Occasionally, herpesviruses may be involved. Bacterial conjunctivitis is commonly caused by bacteria such as Haemophilus influenzae and sometimes by other bacteria like Pseudomonads. Understanding the cause is important because it influences the type of discharge produced and the treatment approach.

Viral and bacterial conjunctivitis can be distinguished by the type of eye discharge and symptoms. Viral conjunctivitis typically produces a watery discharge and does not cause the eyelids to stick together. It is often associated with other viral symptoms like respiratory infections. In contrast, bacterial conjunctivitis usually results in a thick, mucopurulent discharge that is green or yellow in color. This discharge often causes the eyelids to feel stuck shut, especially after sleeping. Recognizing these differences helps in diagnosing the type of conjunctivitis and deciding on appropriate treatment.

Treatment for conjunctivitis depends on whether it is viral or bacterial. Viral conjunctivitis generally has no specific antiviral treatment and usually resolves on its own within one to two weeks with supportive care, such as maintaining eye hygiene and using artificial tears. Bacterial conjunctivitis, however, can be effectively treated with antibacterial eye drops or ointments, which help clear the infection and reduce symptoms. Prompt treatment of bacterial conjunctivitis is important to prevent complications and reduce contagion.

Conjunctivitis is highly contagious because the conjunctiva is exposed to the environment and easily infected by viruses or bacteria that spread through direct contact with infected secretions or contaminated surfaces. Both viral and bacterial conjunctivitis can spread rapidly, especially in close-contact settings like schools or workplaces. Precautions include frequent hand washing, avoiding touching or rubbing the eyes, not sharing personal items like towels or makeup, and staying home when infected to prevent transmission. These measures help control outbreaks and protect others from infection.

While conjunctivitis is usually mild and self-limiting, untreated cases, especially bacterial conjunctivitis, can lead to complications. These may include more severe eye infections, corneal ulcers, or scarring, which can impair vision. Persistent inflammation can also cause discomfort and prolonged symptoms, leading to missed school or work. Early recognition and appropriate treatment are important to prevent these complications and ensure a full recovery.