Allergic Reactions and Risk of Vulvodynia

Purpose: A recent histological study of vestibular tissue from women with localized vulvodynia found universal presence of mast cells compared to no presence in vestibular tissue among controls. Since histamine is generated by mast cells, and mast cells contribute to the production of cytokines during chronic inflammation, we assessed the association between conditions that elicit a clinically relevant histamine response and vulvodynia. Methods: We studied 239 women with and 239 women without vulvodynia to assess the influence of self-reported allergic reactions antecedent to first development of vulvar pain symptoms among cases, and a matched reference age among controls. Results: Women with self-reported hives prior to first report of vulvar pain or reference age among controls were 2.5 times more likely to develop vulvodynia (95% confidence interval [CI], 1.7-4.4). Those reporting a history of allergic reactions to insect bites were 2.1 times more likely (95%CI, 1.1-4.0), and those reporting a history of seasonal allergies were 2.0 times (95%CI, 1.3-3.2) more likely to develop vulvodynia. Findings were similar in a restricted subset of clinically confirmed cases and matched controls. Conclusions: An altered immuno-inflammatory response to environmentally induced allergic reactions may predispose women to the development of vulvodynia or may be markers of an already heightened immuno-inflammatory response.