Conjunctivitis%20-%20allergic,%20seasonal%20-and-%20perennial Diagnosis
Diagnosis
- Allergic conjunctivitis are usually diagnosed by history & clinical presentation
History
- Personal or family history of other allergic conditions (eg atopic dermatitis, allergic rhinitis, asthma)
Determine Possible Trigger Factors
- Review history with regards to:
- History of exposure to allergens
- House dust mites, animal dander, & feathers are the major allergens implicated in PAC & AKC
- Occupational exposure
- Travel
- Use of eye care products, topical medications, solutions or contact lenses
- History of exposure to allergens
Physical Examination
- Clinical signs are usually bilateral & vary based on patient’s age, mediating cell type & association with other conditions
- Conjunctival chemosis, hyperemia & a predominantly papillary conjunctival reaction
Laboratory Tests
- Rarely needed to make diagnosis of SAC or PAC
- Usually done for academic or confirmatory purposes
Conjunctival Scrapings
- If positive for eosinophils it is strongly suggestive of allergy
- Negative scraping is inconclusive
Cytological Exam of Tear Fluid
- Collect tear sample with capillary tube, spread on slide & stain
- Allergic response is indicated by presence of eosinophils, neutrophils &/or lymphocytes
- Tear histamine or tryptase levels can also be measured
Immunoassay Testing of Tear Fluid
- Measure mast cell’s activity by determining the level of tryptase using immunoassay testing