Son with pet allergy

My eight-year-old son has pet allergy ,but his tests came up negative. Anyone ever have this problem?

We used to have a dog, but we got rid of her, and he felt so much better! He is getting sick this year in school as his reactions to pet dander have gotten worse. He now gets hives, post nasal drip, nausea, and red itchy eyes.

How is he getting sick? Do you still have pets at home? dogs? cats?

 

Our daughter has a very very bad dog allergy. She has been in the ER just from what kids at school have on them from home. She carries an epi pen and we have to stay away from all places that have a dog or have had a dog in them. She is good around cats, horses, and all other animals. Her recent blood test show she is getting worse. It all started when she was 9 months old. 

Has the doctor done blood test or skin test?

Where were the tests conducted eg was in a hospital or allergy clinic. What method was used to test. I'm wondering if your son may have multiple allergies too. 

When my children  were young I had similar problems. They were tested by a hospital and the results were negative. I then went where they used the provocation and neutralisation technique. There were multiple allergies including animal dander, certain foods and chemicals. What I am wondering is it possible these allergies are not just contained to pets and what they're eating but other exposures too causing these reactions?