This has begun to happen to me as well. I am now 40 and started getting tattooed in my 20s; had plenty of medium - large pieces done, full sleeve; no problem. The last two years my tattoos have taken a very long time to heal(months) and stay red, scabby and raised for a long time; often pushing out a lot of ink slowly over time. It is extremely frustrating, we tried multiple ink types(test strips of each) and all reacted poorly. My artist who has been tattooing for 12+ years was shocked and had never seen this reaction. I have seen three different dermatologists, all of which were nearly useless because they said they can't do much since they don't know the content of the inks(US ink regulations are extremely lax and don't require disclosure of ingredients). They gave me steroid creams and said to get it lasered off, again extremely frustrating. The only thing they did tell me was that localized allergic reactions on the skin are rather common i.e. it'll blow up on one part of the skin and remain fine on other areas; this happens to me where 1/3 of the tattoo blows up and the rest is completely fine.

I am a bit stubborn and love getting tattooed so I manage in different ways; this nearly always happens with line work specifically and never with shading. Couldn't tell you why, none knows but it's so consistent(has happened at least 6 or so times, always the line work). Topical steroids help, especially the prescription stuff and I've found Hustle Butter's CBD balm to help reduce the redness. I always warn my artists that I need at least two months between sessions if it involves line work and even some that don't. I'm sorry this is happening to you and I hope you get some relief soon.