Chronic urticaria associated with malignancies: A review article

BACKGROUND: Chronic urticaria is a cutaneous disorder defined by the presence of hives and flare for over six weeks. Etiology of chronic urticaria is not clear in 80 to 90 percent of patients. Malignancies are possible associations with allergic disorders such as urticaria. The purpose of this article was to review the expression of chronic urticaria with various malignancies. METHODS: We searched in PubMed, Scopus, and EMBASE databases in English using the keywords chronic urticaria, urticarial, malignancy, and cancer. Inclusion criteria were both full and brief articles, case reports, case series, and original article up to June 2018. RESULTS: We found 258 articles on the primary search. After screening by two researchers, 23 articles were included. Most studies failed to find a link between hives and malignancy. Four studies showed a relationship between hives and malignancy. Five studies showed no relationship between hives and malignancy, and suggested that urticaria could even have a protective effect. As there were no homogenous results, we could not write a metaanalytic study. CONCLUSION: The relationship between chronic urticaria and malignancy is not clear. We need a more organized researches to clarify the association between urticaria and malignancies.