Within the last few days I've noticed many bumbs growing on my 6 month old tattoo. They're exremely itchy and painful. They're about the size of pimples, and it's only growing on the blue ink. It's my first tattoo and took a while to heal as it formed a hard crust on the surface of my foot, once that had healed I've had no problems until now. Does anyone have some sort of answer as to what this might be and what to do about it?? Thank you