Medical studies done many years ago suggested that some allergic disorders seemed to occur with increased frequency among patients with thyroid problems. Unfortunately, this is an area that has received little study during recent years when thyroid tests have become accurate and specific.
Therefore, it is not possible to say whether these conditions are indeed more common in patients with thyroid problems than in the general population. Some patients who have or who have had thyroid problems seem to have a greater than normal tendency to develop hives from time to time. These red itchy welts on the skin do not necessarily come at times when the thyroid is malfunctioning. They generally respond to treatment with antihistamine drugs.
New research suggest that some people with hives and a positive antithyroid (anti-TPO) antibody test may have fewer hives if they take thyroid hormone treatment even if their thyroid hormone levels are normal. If this is your situation ask your physician if thyroid hormone treatment could help you.