Urticaria is classified, according to its duration, as acute and chronic. The latter itself is subdivided into spontaneous and inducible. Autoimmunity can play a role in the development of chronic spontaneous urticaria. Antithyroid autoantibodies, especially anti-thyroid peroxidase, represent the close connection between urticaria and autoimmune pathology of thyroid gland, determining the comorbidity of these conditions that is not seldom observed in clinical practice. Thyroid disfunction should also be considered in idiopathic angioedema (with unknown etiology). In chronic spontaneous urticaria, associated with Hashimoto’s thyroiditis, can be found subclinical hypothyroidism, alongside autoimmune activity. Improvement of urticaria / angioedema symptoms after hormone therapy with levothyroxine in appropriate doses proves the impact of thyroid autoimmunity on the emergence and progression of the cutaneomucosal manifestations.The rare clinical case we present contributes to clarification of the association between marked cutaneomucosal alterations and immunologically active autoimmune thyroiditis, emphasizes the significance of early and directed testing of thyroid hormones and autoantibodies in patients with urticaria / angioedema and shows the favorable therapeutic effect from adding L-Thyroxine to treatment regimen. Interdisciplinary collaboration between specialists in allergology and endocrinology is important in terms of opportune and accurate diagnosing in associated with Hashimoto’s thyroiditis cases of urticaria / angioedema. The full text of the article can be read here.