RESUMO
Although there are several studies showing the association between cancer and urticaria, the mechanisms by which these events occur are not yet known. In this report, a case of acute urticaria with a diagnosis of thyroid papillary carcinoma is presented. Disappearance of treatment-resistant urticarial lesions after thyroidectomy suggests that this association was not a coincidence. The fact that urticaria which was nonresponsive to treatment disappeared spontaneously as a result of tumorectomy, strongly suggests that this association is not a coincidence. To our knowledge, this is the first report of the coexistence of acute urticaria and thyroid papillary carcinoma. This case provides further support that detailed history taking and a thorough physical examination are of paramount importance.