title: Hidradenitis suppurativa is a systemic disease with substantial comorbidity burden: a chart-verified case-control analysis.
abstract: BACKGROUND
  Hidradenitis suppurativa (HS) is a chronic inflammatory disease involving intertriginous skin. Previous epidemiologic studies have been limited by small sample size.
  
  
  OBJECTIVE
  We sought to describe the prevalence and comorbidities of HS in a large patient care database.
  
  
  METHODS
  In this retrospective case-control study, we chart-validated all patients within a hospital database who received at least 1 billing code for HS between 1980 and 2013. Verified cases were matched with controls based on age, gender, and race. Prevalences of a priori selected comorbidities were compared between HS and control groups.
  
  
  RESULTS
  A total of 2292 patients at Massachusetts General Hospital received at least 1 code for HS. A total of 1776 cases had a validated diagnosis of HS, yielding a prevalence of 0.08%. In unadjusted analysis, all comorbidities were diagnosed significantly more in HS compared with control including (in rank order of likelihood): smoking, arthropathies, dyslipidemia, polycystic ovarian syndrome, psychiatric disorders, obesity, drug dependence, hypertension, diabetes, thyroid disease, alcohol dependence, and lymphoma (all P < .01).
  
  
  CONCLUSIONS
  Control subjects were not validated for absence of HS and comorbidity validation was not performed for either group.
  
  
  CONCLUSIONS
  Our results highlights the high comorbidity burden of patients with HS compared with matched control subjects.
authors.affiliation: Clinical Unit for Research Trials and Outcomes in Skin, Massachusetts General Hospital, Boston, Massachusetts; Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts; Alpert Medical School, Brown University, Providence, Rhode Island.
authors.forename: Julia
authors.initials: J
authors.lastname: Shlyankevich
authors.affiliation: Alpert Medical School, Brown University, Providence, Rhode Island.
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Chen
authors.affiliation: Clinical Unit for Research Trials and Outcomes in Skin, Massachusetts General Hospital, Boston, Massachusetts; Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
authors.forename: Grace E
authors.initials: GE
authors.lastname: Kim
authors.affiliation: Clinical Unit for Research Trials and Outcomes in Skin, Massachusetts General Hospital, Boston, Massachusetts; Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts. Electronic address: harvardskinstudies@partners.org.
authors.forename: Alexandra B
authors.initials: AB
authors.lastname: Kimball
mesh_terms: D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000453:epidemiology; D016022:Case-Control Studies; D015897:Comorbidity; D016208:Databases, Factual / Q000706:statistics & numerical data*; D003920:Diabetes Mellitus / Q000453:epidemiology; D050171:Dyslipidemias / Q000453:epidemiology; D005260:Female; D017497:Hidradenitis Suppurativa / Q000453:epidemiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008223:Lymphoma / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology; D013959:Thyroid Diseases / Q000453:epidemiology
keywords: acne inversa; cardiovascular disease; comorbidities; hidradenitis; hidradenitis suppurativa; lymphoma; metabolic syndrome; obesity; prevalence