Hi Tamara – Please check with your doctor ASAP on this. For a mild rash, some docs will have the patient continue taking the anti-thyroid meds along with an anti-histamine. For more serious cases, the meds might need to be reduced or discontinued. Your doctor is in the best position to make this call.
To add to ewmb’s comment, you might check with your pharmacy to see if they have switched from brand to generic…or if they are now using a different manufacturer.
Best of luck!