[Chronic spontaneous urticaria with overlapping type I/IIb endotypes in a patient with Graves disease]

Urticaria is defined as the presence of hives, angioedema, or both. 1028% of patients have autoimmune diseases. Twenty percent have antithyroid antibodies, and only 510% present with symptoms. Two main endotypes are currently recognized: type I (anti-allergic) with IgE anti-TPO autoantibodies, and type IIb (autoimmune) with IgG antibodies and IgE anti-FcER1. However, 51% of patients have a I/IIb overlap.

Clinical presentation: A 46-year-old female with a history of untreated hyperthyroidism presented with generalized pruritic hives with facial angioedema, with more than 50 hives per day, lasting <24 hours, which disappeared without leaving a residual macule, with pruritus of 10/10, interfering with sleep and quality of life, and no triggering factor. Laboratory tests: Eo 5.3% (260), IgE T 471, TSH 0.005, FT4 1.65, C3 138, C4 30, Anti-TPO 219, anti-TG 332. Positive autologous serum test. Evolution: Treatment with levocetirizine 10 mg every 12 hours was started; after 2 months, symptoms decreased.

There are no specific statistics on the combined prevalence of hyperthyroidism and chronic urticaria worldwide. In this case, the patient presents elevated IgE, autoimmune disease, and positive autologous serum, leading to a diagnosis of type I/IIb overlap. Currently, there is no classification system for urticaria types that can be applied to any clinical setting, which impacts the patients therapeutic and prognostic decisions.