Conjunctivitis: Causes, Symptoms, and Treatments

Minsung
Jan 25, 2022
3 min read

Conjunctivitis, widely known as “pink eye,” is an inflammation of the conjunctiva, which is a transparent membrane that covers the surface of the eye. Although conjunctivitis is not a life-threatening condition, the social impact of conjunctivitis is undeniably large due to its prevalence. As the name suggests, a common symptom of pink eye is the reddish color in the white of the eyes. Other possible symptoms are swelling of the conjunctiva or eyelids, itchiness in eyes, sticky discharge, and increased tear production. The three main causes of conjunctivitis are viruses, bacteria, and allergies.

IMG Credit: visioncenter.org

Viral Conjunctivitis

Conjunctivitis can occur with viral infection, and this type takes up 80% of conjunctivitis cases. Adenoviruses are usually responsible for the infection, while other viruses such as the enteroviruses or herpes simplex virus can also cause the condition. A patient with viral conjunctivitis may also display symptoms of a respiratory infection, such as the common cold. The viral infection usually starts in one eye and spreads to the other eye, and symptoms can last from one week to three weeks.

Patients with viral conjunctivitis must take measures to prevent transmissions, as viral conjunctivitis is very contagious. Patients should thoroughly wash their hands after touching their eyes or nasal secretions, should not use towels or pillows with others, and should not use swimming pools. Since viral conjunctivitis is self-limiting, treatments are usually those that relieve symptoms and help the recovery process. Patients will usually rely on the immune system to actually get rid of the disease. In the case of more serious infections such as those from the herpes simplex virus, the doctor may also prescribe antiviral medication.

Bacterial Conjunctivitis

Bacterial infection can also give rise to conjunctivitis. Some common types of bacteria responsible for these infections are Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, etc. Bacterial conjunctivitis commonly involves yellow and sticky discharge from eyes. Similar to viral conjunctivitis, bacterial conjunctivitis is also quite contagious, so good hygiene measures are required to prevent transmission. According to the Centers for Disease Control and Prevention (CDC), bacterial conjunctivitis most commonly occurs during months between December and April.

Antibiotics in the form of eye drops may be prescribed to patients with bacterial conjunctivitis, as antibiotics may help patients overcome the infection more quickly. In mild cases, symptoms may get better quickly without involving the use of antibiotics. The best treatment should be determined through discussing with a doctor.

Allergic Conjunctivitis

Conjunctivitis can also be a result of allergic reactions. Allergens such as pollen, dust, and skin care products can give rise to abnormal immune responses in the eye; immune cells in the conjunctiva can release a chemical called histamine, which causes conjunctivitis symptoms such as inflammation, itchiness, and increased tear production. Allergic conjunctivitis can be accompanied with other allergic symptoms such as a runny nose or a sore throat. Since the condition is associated with the presence of allergens and not viruses or bacteria, allergic conjunctivitis is not contagious.

Structure of Histamine▲ (IMG Credit: PubChem)

For patients with allergic conjunctivitis, avoiding environments with the allergens can be the best option to reduce symptoms. Anti-inflammatory eye drops, tear supplements, and cold compresses may also be prescribed by the doctor to help relieve symptoms.

Prevention Measures

Good hygiene is crucial in preventing viral and bacterial conjunctivitis. Frequently wash hands with soap and avoid touching your eyes, especially if you are around people with conjunctivitis. If you have conjunctivitis, do not share pillows, towels, eye drops, or makeup brushes with others. Also, do not use contact lenses until your doctor permits, do not swim in pools, and frequently wash items such as pillowcases and towels. Contact lenses and makeup brushes that were used while infected may also need to be disposed of to prevent re-infection.