Causes of Conjunctivitis

If your eye becomes red and irritated let your eye doctor take a look. Causes of Conjunctivitis

Determining that you have conjunctivitis is usually easier than determining how your conjunctiva became inflamed. However there are a few common culprits that you should know about. Click here to learn more about conjunctivitis. If your eye becomes red and irritated let your eye doctor take a look. The irritation could be due to something very simple and benign but it also could be the early stages of something much more serious.

Bacterial infection

As one of the most common infections on the planet bacterial conjunctivitis is usually self-limiting but it can escalate to something more serious. Bacterial infection can also sometimes signify a severe underlying systemic disease.

If one were to go out and take culture swabs from the eyes of 100 random people on the street it’s highly probable to find that all of them would have bacteria growing on their conjunctiva. Fortunately there are built-in defense mechanisms preventing these bacteria from multiplying and causing infection. It’s when something happens to lower our defense mechanisms that these bacteria seize the opportunity to cause infection.

Conjunctivitis spreads easily and quickly. Here’s a typical sequence of events: I have conjunctivitis. I rub my eyes. I touch a doorknob or shake hands with you. You rub your eyes. You have conjunctivitis.

Viral infection

Adenovirus Viral infection of the conjunctiva is extremely common. Of all the viruses that can cause conjunctivitis adenovirus the ever-present virus that lurks in our nose throat and upper respiratory airway is probably the most common. Adenovirus can spread like wildfire and the infection can cause significant discomfort to an individual. Unfortunately it can also persist for weeks.

Frequent hand washing is important as adenoviruses are hearty. A virus from an infected person can survive on a counter top refrigerator handle or door knob for several days just waiting to be picked up by its next victim.

If there were one eye infection more deserving of the term ‘pink eye’ it would be adenoviral infection for the inflammation in these infections causes the eyes to turn a very pink color.

Type I herpes simplex

Another not-uncommon cause of viral conjunctivitis is the herpes virus. Type I herpes simplex better known as “above-the-waist” herpes has at one time or another infected over 90% of the population. This form of herpes which is not the sexually-transmitted form of the disease initially manifests as a flu-like illness in childhood. The problem is in most people the virus remains in the body existing in a dormant state in the nervous system. Periodically usually during times of stress the virus becomes activated and causes infection usually in the form of cold sores of the lip skin rashes or eye infections.

Currently there are no medications to treat adenoviral infection but if it is caught early its discomfort can be minimized. There are several medications to combat (not cure) herpes eye infections. However the virus continues to run its course in some individuals being a major cause of severe corneal scarring that could require transplantation.

Most viral conjunctivitis although usually benign and self-limiting tends to follow a longer course than acute bacterial conjunctivitis lasting for approximately 2-4 weeks.

What’s the best way to get a viral infection?

Don’t wash your hands. Another way that viral particles are passed from person to person is through respiratory droplets. When an infected person sneezes zillions of contaminated droplets enter the immediate airspace. These particles are picked up by air currents and can easily drift into another person’s airspace and then inhaled. If some of these freely floating droplets happen to land on your conjunctiva there could be trouble ahead in the form of full blown conjunctivitis or worse yet a cold or the flu. Viruses can also be passed on through contaminated swimming pools and spas.

Allergic conjunctivitis

Since the conjunctiva is a mucosal surface similar to the nasal mucosa the same particles that trigger hay fever or allergic rhinitis may also trigger an allergic conjunctivitis.

Common pollen and airborne particles from grasses and weeds can trigger an allergic reaction. These particles can provoke the symptoms of acute allergic conjunctivitis which include: itching redness burning and tearing. Allergic conjunctivitis can be a seasonal disorder or it can plague certain individuals throughout the course of the year.

What does conjunctivitis look like?

All too often medical textbooks make it sound as if the differentiation of viral and bacterial conjunctivitis couldn’t be more obvious. This is not always the case as these two infections often have very similar clinical manifestations. In both cases the eyes are red though viral infections tend to be more brilliantly red. Another point of differentiation is the type of discharge. Usually viral infections trigger a characteristic watery discharge whereas the discharge in a bacterial infection is typically thick and mucous-like with a yellow-green color. Both infections can show signs of irritation swelling and pain.

Allergic conjunctivitis too presents as a red swollen irritated eye. But what gives allergy away is the characteristic itching. To eye doctors itching means allergy until proven otherwise. Allergic conjunctivitis sufferers usually have a lot of mucous strands in their eyes.

Treatment of conjunctivitis

To combat conjunctivitis that is due to a bacterial infection there are some very potent antibiotics that can be of help. However there are no anti-virals at this time that eradicate the herpes virus from the body. There are medications that will stop the infection in its tracks but the virus will continue to live in the nervous system. No cure or method to kill adenovirus yet exists. When patients are infected with adenovirus therapy is directed towards minimizing symptoms and tissue damage.

Treatments for allergic conjunctivitis consist of a host of relatively new medications designed to suppress the allergic response and minimize the patient’s symptoms.

See your eye doctor

If your eye is red swollen or painful it’s important that you see your eye doctor right away. Don’t assume that your eyes are red because you didn’t get enough sleep or because you had too much to drink. If you do have an infection it’s important that the fire is put out immediately before any tissue damage takes place.