You might consider taking an oral antihistamine as well as using antihistamine eye drops. I have a huge allergy to cats and sometimes when I have contact with someone who has a cat and I am away from my eyedrops I use an ice cube placed over my closed eye. It tends to bring down the swelling as well as rinse the allergen out of the eye as the cube melts. I wish you good luck. Itchy eyes are maddening.