Why do Allergies Cause Itchy Eyes?

Spring is often a welcome change from winter with its milder weather and blooming flowers, but it can also be miserable if you are prone to allergies. Allergies tend to peak in spring as pollens fill the air. When your body has an allergic reaction, it tries to fight off pollen and other triggers by releasing chemicals into the body. This is actually a very silly idea because the pollens aren’t harmful to your body, so the attack is a wasted effort.

Allergies Cause Itchy Eyes

(Pixabay / MariangelaCastro)

So why does your body overreact to innocent allergy triggers? The answer is that your immune system gets a little confused. Instead of just ignoring allergens, it mistakes them for insidious germs and bacteria. Your immune system then kicks into overdrive, unleashing chemicals such as histamine. The chemicals cause a number of reactions, but chief among them is inflammation. When your nasal passage swell, you get a stuffed up nose. When your airways swell, you get asthma. When the lining of your eyes (conjunctiva) swells, you get the dreaded conjunctivitis.

The symptoms of allergic conjunctivitis include:

  • Itchy, stinging eyes
  • Teary eyes
  • A pinkish hue on the eyeball’s surface (caused by inflamed blood vessels)
  • Mucus discharge
  • Eye irritation (like a feeling of sand in the eye)

Types of conjunctivitis

Conjunctivitis is often allergic in nature, but it may also be viral. Viral conjunctivitis will come and go like the common cold. It is highly contagious and can be spread through sneezing and coughing. Conjunctivitis can also be bacterial, meaning that it develops in response to bacteria that affect your eye, and can usually be treated with antibiotics. Bacterial conjunctivitis may also be contagious.

Allergic conjunctivitis is not contagious. You will notice it flaring up, often repeatedly, in response to allergens in your environment such as dust, pet dander, or seasonal pollens.

Treatment for allergic conjunctivitis

Allergic conjunctivitis can be relieved by antihistamine eye drops (over-the-counter or prescription). If you find that the eye drops are not effective or that you are having to take them for extended periods of time because your conjunctivitis persists, you may be a candidate for allergy immunotherapy.

Allergy immunotherapy is available through allergy shots or sublingual immunotherapy (under-the-tongue allergy drops). Both of these treatments can help your immune system stop overreacting to allergens in the environment. When your immune system is desensitized, it will stop reacting with irritating symptoms such as conjunctivitis.

Allergy injections must be administered at the doctor’s office, but sublingual immunotherapy is safer than shots so it can be taken at home. Talk to your doctor about prescribing sublingual immunotherapy or allergy shots to treat persistent allergic conjunctivitis.