Allergic eye disease
How is it diagnosed?
 |
| Papillae on the inner surface of the eyelid |
Allergic eye disease is usually diagnosed by considering two things:
- The symptoms described by a patient
- Changes in their conjunctiva, eyelid and cornea
Symptoms
Patients with allergic eye disease complain of one or more of the following:
- Itch. This is the most important symptom of all. If there is no itch, it's almost certainly not allergy. If there is itch, allergy is almost always present.
- Redness
- Wateriness
- Swelling of the conjunctiva and eyelids
Changes in the eye and eyelids
The signs of allergic eye disease include:
- Redness
- Wateryness
- Papillae
- Lid swelling
- Dark rings around the eyes ('allergic shiners')
Tests for allergy
It is very unusual to specifically test for an allergic response. Most patients quickly identify what causes their allergy.
Patch testing has quite limited value in making the diagnosis, changing the severity of the disease or the way a patient is treated. Most individuals can’t avoid the allergen to which they are sensitive.
Distinguishing allergic conjunctivitis from infective conjunctivitis
Several features help distinguish allergic conjunctivitis from other causes of conjunctivitis. The table below gives an overview of the main differences between the two diseases.
| Allergic conjunctivitis | Infectious conjunctivitis |
| Recurrent or chronic | One-off |
| Other allergies (asthma, hayfever, eczema) | Other infection (cold or flu) |
| Itch | Grittiness |
| Watery discharge | Sticky discharge |
| Develops during day | Worse in morning |
| Lymph nodes normal | Swollen lymph nodes |