A previously healthy 38-year-old woman developed chronic urticaria. Her initial laboratory evaluation had included normal thyroid function tests and mildly elevated thyroid peroxidase antibodies. Because she responded poorly to standard therapy with antihistamines and corticosteroids, she was referred to endocrinology for assistance with clinical management. A brief therapeutic trial of levothyroxine had no impact upon the frequency or severity of urticaria; the patient then self-discontinued her medication. Two months later, she developed new complaints of heat intolerance, diaphoresis, and diffuse myalgias and arthralgias. Subsequent laboratory studies confirmed new-onset hyperthyroidism, with a thyrotropin level of <0.01 mU/L, elevated thyroxine levels, and high levels of thyroid-stimulating immunoglobulin (352%). Nuclear imaging studies confirmed the clinical diagnosis of Graves disease. Hyperthyroidism responded to medical therapy with propylthiouracil; however, her chronic urticaria lesions increased in both frequency and severity. After conversion to methimazole failed to affect her clinical course, the patient elected a near-total thyroidectomy. Within just 10 days of surgery, her skin lesions improved dramatically; urticarial lesions then resolved completely within several weeks. In this report, we first discuss the well-documented association between chronic urticaria and autoimmune thyroid disease. We then review the existing (and controversial) evidence for treating thyroid autoimmunity in patients with chronic urticaria.
*Clinical Instructor and †Assistant Clinical Professor, Section of Endocrinology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
Dr. Goldberg has disclosed that he is on the speakers bureau for Eli Lilly and Company and is a consultant for Novo Nordisk. Dr. Mayerson has disclosed that he was/is on the speakers bureau for Novo Nordisk, Merck, Abbott, and Novartis and was on the speakers bureau for Sanofi-Aventis. Dr. Mayerson also was/is a stock shareholder of Merck stock.
The authors have disclosed that the use of thyroid medication has not been approved by the U.S. Food and Drug Administration (thyroid hormone or thioureas) for chronic urticaria associated with thyroid autoimmunity. Please consult product labeling for the approved use of these drugs.
Lippincott Continuing Medical Education Institute, Inc. has identified and resolved all faculty conflicts of interest regarding this educational activity.
Reprints: Philip A. Goldberg, MD, Clinical Instructor, Yale University School of Medicine, Endocrine Associates of Connecticut, 6 Business Park Drive, Suite 304, Branford, CT 06405. E-mail: firstname.lastname@example.org.
Chief Editor's Note: This article is the 21st of 36 that will be published in 2007 for which a total of up to 36 AMA PRA Category 1 Credits™ can be earned. Instructions for how credits can be earned precede the CME Examination at the back of this issue.