Allergic conjunctivitis

Other terms

• Spring conjunctivitis
• Vernal conjunctivitis

Definition

Allergic conjunctivitis is an inflammation of the conjunctiva, the membrane that lines the inside of the eyelids and the sclera (the whites of the eyes). It is caused by the presence of an allergen which, on coming into contact with the surface of the eye, provokes an allergic reaction.

There are two main forms of allergic reaction:

• Seasonal allergic conjunctivitis, which most often appears with the arrival of spring and pollens (acute conjunctivitis),
• Per-annual allergic conjunctivitis, which is mainly due to house dust mites or animal hairs, and can persist for as long as the allergens are present (chronic conjunctivitis).
   

Symptoms

The main symptoms, which in most cases affect both eyes in the same way, are :

• a stinging, burning sensation in the eyes
• severe itching of the eyelids
• Watery eyes
• Watery secretions
• Red conjunctiva, giving the eyes a swollen appearance
• Rhinorrhea
• Chemosis

Diagnostic

Allergic conjunctivitis is diagnosed by a doctor through examination of the eye and symptoms.

Treatments

The treatment of allergic conjunctivitis combines :

• Artificial tears, which reduce discomfort and dryness while cleansing the eye of allergens.
• Antihistamines and/or mast cell stabilizers, which calm inflammation and symptoms by preventing the release of histamine.

Topical antihistamines are often preferred to per os antihistamines, which are nevertheless very useful when allergy symptoms are also present in the nose, throat or ears.

Frequency

Allergic conjunctivitis affects around 20% of the population, but the degree of damage can vary.

Prevention

To prevent the risk of allergic conjunctivitis, exposure to potentially allergenic substances should be avoided as far as possible, especially for people with atopic tendencies.

References

Conjonctivite allergique - Troubles oculaires - Manuels MSD pour le grand public (msdmanuals.com)

Oeil_rouge_2010 (hug.ch)