Urticaria and comorbidities

Urticaria is a mast cell (MC)-driven skin disease. Degranulation of these cells is triggered by the activation of several receptors on its surface. The activation of MC in chronic spontaneous urticaria (CSU) appears to be associated with an autoimmune etiology. Certain comorbidities such as autoimmunity, infections, allergy, emotional stress, and metabolic syndrome are frequently associated with chronic urticaria (CU). The objective of this review is to highlight the frequent association between CU and several comorbidities, which can lead to a worse prognosis for the underlying disease. We searched for original and review articles on CU and comorbidities in PUBMED, abstracts published in AAAAI and EAACI; all of them in English. Our review reinforced how CSU, being itself an autoimmune disease, is strongly linked to several other autoimmune diseases. Besides autoimmunity, emotional stress was considered another frequent comorbidity associated with CU and also a trigger factor for urticaria exacerbation. Some studies recently considered CU as a low-grade chronic inflammatory condition and may be associated with metabolic syndrome. In conclusion, CU is considered a heterogeneous disease with distinct clinical features. It is worth remembering that CU should not be considered just a skin disease and its complete control could minimize a worse clinical outcome.