title: Severe teenage acne and risk of endometriosis.
abstract: OBJECTIVE
  Is there a relationship between severe teenage acne and endometriosis?
  
  
  CONCLUSIONS
  Endometriosis is positively associated with severe teenage acne.
  
  
  BACKGROUND
  No studies have specifically explored a possible association between severe acne in adolescence and risk of endometriosis.
  
  
  METHODS
  This prospective cohort study used data collected from 88 623 female nurses from September 1989 to June 2009 as part of the Nurses' Health Study II (NHS II) cohort.
  
  
  METHODS
  Regression models were used to calculate hazard ratios (HRs) and confidence intervals (CIs) for endometriosis among women with and without severe teenage acne. Multivariate models were adjusted for established risk factors of endometriosis.
  
  
  RESULTS
  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 = 1.20, 95% CI: 1.08-1.32). The association was not affected by adjusting for use of tetracycline or isotretinoin.
  
  
  CONCLUSIONS
  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.
  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.
  
  
  BACKGROUND
  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-GA-2011-302078). 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.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA jix719@mail.harvard.edu jialhan@iu.edu.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA.
authors.forename: Marina
authors.initials: M
authors.lastname: Kvaskoff
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA.
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Clinical Research Program, Department of Dermatology, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Clinical Research Program, Department of Dermatology, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA.
authors.forename: Abrar A
authors.initials: AA
authors.lastname: Qureshi
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Missmer
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA Clinical Research Program, Department of Dermatology, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA Department of Epidemiology, Fairbanks School of Public Health, Simon Cancer Center, Indiana University, Indianapolis, IN, USA jix719@mail.harvard.edu jialhan@iu.edu.
authors.forename: Jiali
authors.initials: J
authors.lastname: Han
mesh_terms: D000152:Acne Vulgaris / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D015897:Comorbidity; D004715:Endometriosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D012306:Risk; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: acne; diagnosis; endometriosis; epidemiology; screening