Other Talks in the Series: Skin Biology

The lab evaluation for chronic urticaria is something that we should keep in mind but not always perform. We should keep it focused based on the history and physical exam. For example, you might obtain a CBC with differential or liver function tests if the patient has hepatosplenomegaly or other findings in the history of physical suggestive of lymphoma or other cancers. Eosinophilia might suggest a parasitic infection. And in that case, you might order a stool study for ova and parasites. A TSH and Free T4 could be obtained if the patient has symptoms consistent with hyper or hypothyroidism. And if you note below, I've also listed thyroid antibodies likes TPO or thyroglobulin antibodies, which have been associated with chronic urticaria among other autoimmune and immune complex diseases that are associated with other abnormalities and complements, abnormalities in the ESR or ANA. So if you're suspecting an autoimmune or immune complex disease, those labs are important to obtain. But I wouldn't necessarily order them on regular basis. I would allow the history and physical to guide me in this. The guidelines from the American Academy of Allergy, Asthma, and Immunology, and the EAACA, the European groups also focuses on this that it's important to not obtain these labs on a regular basis, because usually, the history and physical should be able to guide you as to whether these are important to obtain. The last aspect of this slide antibody against the Fc epsilon receptor alpha, which has been found in research to be associated with chronic urticaria in select cases. However, it's not recommended to obtain this lab in routine evaluation of the patient with chronic urticaria, because it doesn't help guide us in the management of the patient. So usually, it's still only obtained for research and interest purposes.