title: Dermatologic disorders in 118 patients with autoimmune (immunoglobulin G4-related) pancreatitis: a retrospective cohort analysis.
abstract: BACKGROUND
  Autoimmune pancreatitis is the prototypical manifestation of immunoglobulin G4-related disease, a fibroinflammatory syndrome that can affect virtually any organ. Rarely, skin involvement has been reported in immunoglobulin G4-related disease. Isolated case reports have described other distinct associated dermatoses.
  
  
  OBJECTIVE
  Our objective was to determine the frequency and nature of dermatologic manifestations of immunoglobulin G4-related disease in patients with autoimmune pancreatitis.
  
  
  METHODS
  Retrospective analysis of dermatologic conditions of patients with autoimmune pancreatitis.
  
  
  RESULTS
  Among the 118 identified patients, 31 (26.3%) had a dermatologic diagnosis [mean (standard deviation; SD) follow-up 5.9 (4.6) years]. Two patients (1.7%) had necrobiotic xanthogranuloma; three (2.5%) had another xanthomatous or xanthogranulomatous process. One patient (0.8%) had pemphigus erythematosus. No patient had immunoglobulin G4-related skin disease.
  
  
  CONCLUSIONS
  Skin involvement in immunoglobulin G4-related disease appears to be rare. A disproportionately high number of patients had xanthomatous or xanthogranulomatous processes, including necrobiotic xanthogranuloma. It remains unclear whether the association between immunoglobulin G4-related disease and necrobiotic xanthogranuloma or other xantho(granulo)matous processes represents shared pathophysiology, a mutual underlying driver, or coincidence, though the results of this study cast doubt on the latter. Although pemphigus was not reported in immunoglobulin G4-related disease previously, the prominent role of the immunoglobulin G4 subclass in each condition makes this association intriguing.
authors.affiliation: Department of Dermatology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Kindle
authors.forename: Philip A
authors.initials: PA
authors.lastname: Hart
authors.forename: Suresh T
authors.initials: ST
authors.lastname: Chari
authors.forename: Mark R
authors.initials: MR
authors.lastname: Pittelkow
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Julia S
authors.initials: JS
authors.lastname: Lehman
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D010195:Pancreatitis / Q000276:immunology*; D012189:Retrospective Studies; D012871:Skin Diseases / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G