Severe teenage acne and risk of endometriosis

main results and the role of chance: A total of 4 382 laparoscopically confirmed endometriosis cases were documented during 1 132 272 woman-years of follow-up. Compared with women without a history of severe teenage acne, women who had severe teenage acne had a 20% increased risk of endometriosis (HR ¼ 1.20, 95% CI: 1.08 –1.32). The association was not affected by adjusting for use of tetracycline or isotretinoin. limitations andreasonsf orcaution:The HR is likely to be underestimated since we only included endometriosis cases confirmed by laparoscopy. Although geographically diverse, the NHS II cohort is primarily Caucasian, which may limit generalization to more ethnically diverse populations. widerimplications ofthestudy: The results of this study suggest that severe teenage acne is associated with an increased risk of endometriosis. As a visible and non-invasive clinical indicator, severe teenage acne may be useful for early detection of endometriosis. We bring this counter-intuitive association to the attention of clinicians for the benefit of the patient and an early diagnosis of endometriosis. studyfunding/competing interest: This study was funded by research grant CA176726 from the National Institute of Health. M.K. is supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA2011-302078). The funding agencies had no role in the design of the study, in the analysis and interpretation of the data, in the writing of the report or in the decision to submit the paper for publication.