Causes
The cause of allergic conjunctivitis is an allergic reaction of the body's immune system to an allergen. Allergic conjunctivitis is common in people who have other signs of allergic disease such as hay fever, asthma and eczema.
Among the most common allergens that cause conjunctivitis are:
- Pollen from trees, grass and ragweed
- Animal skin and secretions such as saliva
- Perfumes
- Cosmetics
- Skin medicines
- Air pollution
- Smoke
- Dust mites
- Eye drops
Most cases of seasonal conjunctivitis are due to pollen and occur in the hay fever season, grass pollens in early summer and various other pollens and moulds may cause symptoms later in the summer.
Perennial conjunctivitis is commonly due to an allergy to house dust mite (a tiny insect-like creature that lives in every home).
Giant papillary conjunctivitis is a very rare condition that is mainly caused by an allergic reaction to "debris". Surgery may also cause this type of allergic conjunctivitis.
Contact dermatoconjunctivitis is caused by the rest of the allergens that conjunctiva may come into contact with: cosmetics, medications and so on.
Read more about this topic: Allergic Conjunctivitis