Viral conjunctivitis can be contagious. It can be prevented to some extent by taking precautions to avoid contracting the virus, such as not touching common areas or your eyes with your hands. However, small children have weak immune systems and often unknowingly rub their eyes with dirty hands. This page introduces the causes, symptoms, and treatments for each type of conjunctivitis.

Conjunctivitis: causes, symptoms, types and treatment

What is conjunctivitis?

The conjunctiva is a semi-transparent membrane that covers the inside of the upper and lower eyelids and the surface of the white of the eye (sclera), and has a structure similar to that of skin. The conjunctiva is rich in small blood vessels and also contains lymphatic tissue, which causes an immune response (the body's response to foreign substances). When a foreign substance adheres to this membrane, an inflammatory reaction occurs. This is conjunctivitis.

What causes conjunctivitis?

Conjunctivitis can have many causes, including infection, allergies, and airborne irritants. Infections can be bacterial or viral.

Symptoms of bacterial conjunctivitis

If conjunctivitis is caused by bacteria such as staphylococcus or streptococcus, your eyes will turn red and produce eye discharge. If you produce a lot of eye discharge, it may be an acute infection, so you should see an ophthalmologist immediately. Chronic inflammation will only produce a small amount of eye discharge when you wake up in the morning.

Symptoms of viral conjunctivitis

If the cause is a virus, in addition to red eyes, cold symptoms such as a sore throat and runny nose will appear. The eye discharge is often runny, and symptoms will last for one to two weeks. Particular attention should be paid to what are commonly called epidemic eye diseases, which include epidemic keratoconjunctivitis, pharyngoconjunctivitis, and acute hemorrhagic conjunctivitis. If the cause is an allergy, the main symptom will be itchy eyes, with eye discharge and redness.

Allergic conjunctivitis

Allergic conjunctivitis manifests as the following symptoms:

• Bloodshot eyes
• Eye discharge
• Watery eye
• Itchy eyes

In particular, the itching that is not seen much in other types of allergic conjunctivitis is the itching that makes you want to rub your eyes. These symptoms occur when a substance called histamine, which is produced by an allergic reaction, stimulates the body.

Epidemic keratoconjunctivitis (pink eye)

Epidemic keratoconjunctivitis, also known as pink eye, causes not only the main symptoms of conjunctivitis, such as bloodshot eyes and eye discharge, but also a gritty foreign body sensation. The eyelids may swell, making it difficult to open the eyes.

Pharyngoconjunctivitis (swimming pool fever)

Pharyngoconjunctivitis is a viral disease that causes not only eye symptoms, but also throat symptoms (redness, pain, etc.) and fever. It is also known as "pool fever" because elementary and junior high school children can become infected at swimming pools.

acute hemorrhagic conjunctivitis

Acute hemorrhagic conjunctivitis is characterized by its sudden onset and bleeding. In addition to eye symptoms such as eye pain, a gritty foreign body sensation, redness, and subconjunctival bleeding, other symptoms include headache, fever, and respiratory system symptoms.

Herpetic conjunctivitis

Conjunctivitis is caused by a virus called herpes, but is not contagious. In addition to symptoms of conjunctivitis such as bloodshot eyes and eye discharge, red blisters may appear on the skin around the eyes.

Flow of conjunctivitis treatment

There are many types of conjunctivitis, so there is no specific cure. Eye drops with anti-inflammatory and antibacterial properties may be prescribed, but these are prescribed only in the hope of having a secondary effect. There is also viral conjunctivitis, so it is important to get plenty of rest and eat a diet that will boost your immune system.

Eye drops used to treat conjunctivitis

Conjunctivitis (hay fever, pink eye) Allergic conjunctivitis (hay fever, etc.) is primarily treated with eye drops that have anti-allergic properties. When the season in which it occurs is known, such as hay fever, starting to use eye drops before symptoms appear can help prevent and reduce symptoms. When symptoms such as itching are severe, eye drops containing steroids are used. However, although they are highly effective at suppressing symptoms, they have side effects, so they must be used while visiting an ophthalmologist. Also, if symptoms do not subside with eye drops alone, anti-allergy medication may be taken orally.

How to prevent conjunctivitis

Conjunctivitis occurs when viruses attached to doorknobs and other objects get into the eyes. Therefore, it can be largely prevented by following the following three points:

• Do not touch areas that other people use
• Do not touch your eyes with your hands
• Wash your hands thoroughly when you come back from outside

It is also important to improve your lifestyle and boost your immunity to prevent viral infections.

Frequently asked questions about the causes, symptoms, types and treatment of conjunctivitis