The testing you are having for allergies to dogs, cats, dust mites, pollen and so on is not the test for Allergic Contact Dermatitis, ACD. This environmental test is usually a simple 30 minute patch test which I've had done several times in my youth. At that time they were testing for hayfever and sinus issues.
Google the 5 Day Extended Patch Test for ACD which takes 5 days with your entire upper back torso covered with at least 50 allergen patches. Because of my contact allergies my body's inflamation was elevated. I have had the True Test Patch kit test done several times, besides separate blood tests. Some of the allergens tested are natural like to rubber, cinnamon, metals and others are to chemicals and drugs like steroids and even antibiotics. You'll learn to read every fiber content of your contacts and ingredients in lotion, cosmetics, grooming products. You learn that so many ingredients, like preservatives in grooming products only serve the benefit of the manufacturer.
With repeated exposure over time the histamine levels in our body increase because they believe these substances are poison and are trying to attack and eliminate them. Eventually the body becomes allergic. Once allergic always allergic.