SYNDROME OF THYROID AUTOIMMUNITY AND IDIOPATHIC CHRONIC URTICARIA AND ANGIOEDEMA

Abstract

<h3>Introduction</h3> Chronic spontaneous urticaria (CSU) does not have a clear etiology in 80-90% of cases; however, it is thought to have an autoimmune mechanism. CSU often accompanies or precedes other autoimmune conditions such as autoimmune thyroid disease (ATD). There are few cases reported where ATD with CSU progresses to anaphylaxis. We present a case of syndrome of thyroid autoimmunity and idiopathic chronic urticaria and angioedema progressing to anaphylaxis. <h3>Case Description</h3> Patient is an atopic female that presented as an 8-year-old to endocrinologist after having abnormal thyroid labs while investigating urticaria since the age of 4-years-old. Endocrinology diagnosed her with autoimmune thyroid disease and started her on levothyroxine. She presented to our allergy service at 10-years-old for chronic urticaria partially responsive to diphenhydramine. Repeat thyroid peroxidase (TPO) antibodies were >1000. She had itch relief after starting cetirizine 10 mg daily and complete relief with 20 mg twice daily. She went on to have two episodes of anaphylaxis requiring hospitalization. Anaphylaxis work up was negative. Months later, we weaned her cetirizine to 20 mg daily where she has remained for the past 1.5 years without further anaphylaxis. <h3>Discussion</h3> Our case illustrates anaphylaxis occurring in the setting of chronic spontaneous urticaria coupled with autoimmune thyroid disease which has rarely been written about. CSU has been found to be concomitant with ATD at higher rates than the general population. These patients may show more refractory urticarial disease. The mechanism is not understood, but this case shows that these patients warrant closer monitoring for anaphylaxis than previously thought.