Medical malpractice is negligence.  Negligence is the failure to exercise due care (that degree of care that a reasonable medical practitioner in the community would have exercised under the same or similar circumstances to prevent foreseeable harm).You would not have a medical malpractice case against the TB test facility for the following reasons: (1) Since your previous TB tests were negative, it was unforeseeable that you would have an allergic reaction to the current TB test.  Negligence requires foreseeable NOT unforeseeable harm; (2) You did not follow the doctor's advice of seeing a specialist at the Dept. of Public Health.  If you had done that, you might not have any remaining marks on your body.