Eye allergy, also known as allergic conjunctivitis, is quite common. They occur when the eyes react to something (allergen) that irritates them. The eyes produce a substance called histamine to fight the allergen. As a result, the eyelids and conjunctiva become red, swollen, and itchy. Unlike other types of conjunctivitis, eye allergies do not spread from person to person.
Eye Allergy Symptoms
The most common symptoms are:
- Red, swollen or itchy eyes
- Burning or watery eyes
- Sensitivity to light
In the presence of nasal allergies, nasal congestion, itching and sneezing may also occur. Also, a headache, itchy or aching throat, or cough may accompany the symptoms.
Eye Allergy Causes
Allergy is when the body’s immune system reacts to an allergen that is normally harmless. When an allergen comes into contact with the eye, certain cells in the eye (called mast cells) release histamine and other substances to fight the allergen. This reaction causes the eyes to become red, itchy, and watery.
Airborne allergens, both indoor and outdoor, cause many eye allergies. These allergens include:
- Pollen from lawns, trees, and ragweed
- Animal dander
Allergic reactions caused by perfumes, cosmetics, or medications can also cause the eyes to develop an allergic response. Some people may be allergic to diluting eye drops or the preservative chemicals in prescribed eye drops. If possible, preservative-free drops should be used instead.
Sometimes, the eyes can react to allergens that are not necessarily in direct contact with the eyes. These can include certain foods or insect bites or stings.
Genetic factors also play an important role in allergic disorders. Some people have eye allergies from their parents. If both parents have an eye allergy, the child is more likely to have an allergy.
Eye Allergy Diagnosis
Eye allergies are best diagnosed by an allergist or someone who specializes in diagnosing and treating allergies. It is especially important to see an allergist if there are other allergy-related symptoms, such as asthma or eczema.
Allergists will first ask about medical history and symptoms, including when they started and how long they stayed. They can then perform a skin prick test to determine the underlying cause of the symptoms.
Eye Allergy Treatment
The first and best option is to avoid contact with substances that trigger eye allergies. In cases where it is not sufficient, the following can be applied:
- Saline eye drops to wash off allergens
- Over-the-counter medications or eye drops (short-term use)
- Prescription medications prescribed by the doctor
- Allergy vaccines (immunotherapy) that the doctor can do
Symptoms may disappear completely when the allergen is eliminated or after the allergy has been treated.