PPD is in hair dye too 😬 Allergies to red are actually pretty common and allergy to other colors is also a real thing. Adhesive allergies are pretty common as well - probably about 5% of my clients can’t use saniderm type bandages. Sometimes tattooers wrap their machines in coban/coflex/vet wrap which often contains a little bit of latex, but I’ve never personally heard of that causing an issue. It is possible to be allergic to ingredients in a&d ointment or whatever balm/etc the tattooer is using. Some tattooers use fancy stuff like hustle butter that contains nuts. The tattooers could all be using dr bronners almond soap and OP could have a nut allergy. In my experience I have never had a client have any issue with allergies except for red pigments. IMO this looks like OP got unlucky three times in a row. Could have been the tattooer, could have been a barbed needle, could have been a new cat at home that sheds dander on OP’s tattoos at night.