Just remembered one of the episodes from doctor House...)))
Don't know if what you are saying is a possibility though....
Some people get weird auto immune reactions from the chemicals in the ink.
I don't know about tattoo ink, but a friend of mine had MS symptoms several years ago. After many tests and having her left side paralyzed and no answers from the docs, her mother did research and found that the mercury used in tooth fillings can leak out into your system and cause a very serious imbalance in your system which in turn caused the MS symptoms. My friend had the old silver fillings removed and replaced with the newer tooth colored (composite?) fillings. She had to take some meds for awhile to restore balance in her system, but in the end was just fine.