Suggest Treatment For Raised Bump On Arm

Question : hello! I would prefer a dermatologist if possible. about 5-6 weeks ago I noticed a pimple on the outside of my arm directly under the line of my tattoo (shown by the arrow in the pictures provided) I left the pimple alone initially and it subsided to half its original size and does not hurt. but at about the one month mark I noticed it had not fully healed and still had a bump under my skin. I admittedly picked at it and squeezed it and it developed a scale over it which recently subsided and I was left with pearly raised skin with still a slight bump its confined to just under the tattoo line... obviously it's difficult to see because its under the tattoo, but I'm reluctant to go to a dermatologist in person who will inevitably try to convince me to get a biopsy which will ruin the tattoo. do you think this is necessary or at this stage do you think it is reasonable to just watch it for changes... I was slightly worried about basal cell carcinoma. but I am hoping it is just trapped dead tissue under the thick ink of the tattoo which cannot escape