Endometriosis and type 1 allergies/immediate type hypersensitivity: a systematic review.

Endometriosis is a chronic and debilitating disorder affecting up to 5-10% of women in reproductive age. Investigators have described deficiency in cellular immunity in women suffering from endometriosis, and in the recent years endometriosis has been linked to other diseases, allergic disease being one of them. The objective of this paper is to systematically review the existing literature on the possible association between endometriosis and allergic disease. This review is based on the recommendations by the preferred reporting of systematic reviews and meta-analysis (PRISMA) statement. PubMed and Embase were searched for studies on women diagnosed with endometriosis and with manifestations of allergic disease who were compared to a reference group. Out of 316 articles screened, 6 were reviewed and 5 ultimately met the inclusion criteria. Four out of the five studies reported a positive correlation between endometriosis and allergic manifestations, including hay fever, sinus allergic rhinitis, and food intolerance/sensitivities (food allergy). Investigators reported an odds ratio (OR) as high as 4.28 (95% CI: 2.93-6.27) for a positive history of allergy among women suffering from endometriosis. Equivocal results were found on asthma prevalence in women with endometriosis. Due to the heterogeneity of the included studies, no meta-analyses could be performed. The available literature clearly indicates that women with endometriosis are at an increased risk of allergic disorders compared to controls, but due to the lack of a concise definition of allergic disease and therefore diagnostic criteria, further studies are needed in order to draw firm conclusions on the association between endometriosis and allergic disease.