My mother, who is 85 years of age, and has thyroid problems for 50 years-had it removed in July of 2005, because she was having hives constantly-Dr. Myers , an endocroligist, recommended she have it removed and she did. Since October of 2013 she has had the hives off and on (twice in the E.R. ). She currently takes 75 mg of synthroid , she is seeing the same allergist as she saw in 2005 who did not send her to the thyroid specialist. Could the build up of synthroid be causing her problem?