Olopatadine Eye Drops and Allergy Skin Testing

Study Overview
=================
Brief Summary
-----------------
Use of olopatadine ophthalmic solution (eye drops) will decrease allergy skin test reactivity.

Official Title
-----------------
Effect of Olopatadine Hydrochloride 0.2% Ophthalmic Solution on Epicutaneous Skin Prick Testing With Histamine and Saline

Conditions
-----------------
Allergic Rhinitis, Allergic Conjunctivitis

Intervention / Treatment
-----------------
* Drug: olopatadine
* Drug: placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Adults aged 18 to 75 years Healthy volunteers (no major illnesses or active symptoms) Exclusion Criteria: Known allergy or hypersensitivity to the drugs or components Pregnant or nursing women Women wishing to become pregnant during the study's duration Use of topical or oral medications with antihistaminic activity for 14 days proceeding randomization Dermatographism as evidenced on skin testing on visit 1 Chronic urticaria active within the past 6 months Severe hypertension Psychiatric diagnoses which could potentially affect medication compliance, such as schizophrenia or delusional disorders, as determined by the investigator obtaining informed consent and based on the subject's past medical history Inability to provide informed consent

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: olopatadine then placebo<br>participants received olopatadine 0.2% opthalmic solution 1 drop into each eye at the same time each day for 7 to 10 days followed by 7-10 day washout period. They then received a placebo, normal saline opthalmic solution 1 drop into each eye at the same time each day for 7-10 days | Drug: olopatadine<br>* olopatadine 0.2% opthalmic solution 1 drop into each eye at the same time each day<br>Drug: placebo<br>* placebo, normal saline opthalmic solution 1 drop into each eye at the same time each day<br>|
| Active Comparator: placebo then olopatadine<br>participants received olopatadine 0.2% opthalmic solution 1 drop into each eye at the same time each day for 7 to 10 days followed by 7-10 day washout period. They then received a placebo, normal saline opthalmic solution 1 drop into each eye at the same time each day for 7-10 days | Drug: olopatadine<br>* olopatadine 0.2% opthalmic solution 1 drop into each eye at the same time each day<br>Drug: placebo<br>* placebo, normal saline opthalmic solution 1 drop into each eye at the same time each day<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Difference in Area (cm2) of the Wheal Size in Histamine Skin Test Response During Treatment With Olopatadine Compared to Placebo. |  | at baseline and at return visit (between study day 7-10) | 
| The Difference in Area (cm2) of the Flare Size in Histamine Skin Test Response During Treatment With Olopatadine Compared to Placebo. |  | at baseline and at return visit (between study day 7-10) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
allergy, skin testing, eye drops, antihistamines