title: Chronic hepatitis C, cryoglobulinemia, and cutaneous necrotizing vasculitis. Clinical, pathologic, and immunopathologic study of twelve patients.
abstract: BACKGROUND
  Several patients with chronic hepatitis C infection and cutaneous vasculitis have been described.
  
  
  OBJECTIVE
  The objective of this study was to define better the features of necrotizing vasculitis and mixed cryoglobulinemia in patients with hepatitis C infection.
  
  
  METHODS
  A retrospective review of 611 patients with hepatitis C antibodies was conducted. Patients with clinical and histopathologic findings of cutaneous necrotizing vasculitis were identified. Clinical, histologic, and laboratory data were recorded.
  
  
  RESULTS
  Twelve patients with necrotizing vasculitis and chronic hepatitis C infection were identified. Palpable purpura was the most common clinical presentation. Onset of skin lesions was usually more than 10 years after infection. The lower extremities were affected in all patients. Cryoglobulinemia of the mixed type II was present in 10 of 11 patients. Liver function tests were evaluated at the time of vasculitis in most of the patients. Rheumatoid factor was elevated in all nine patients tested. Total complement was decreased in seven of nine patients, and C4 was decreased in six of seven patients.
  
  
  CONCLUSIONS
  Cutaneous vasculitis associated with cryoglobulinemia and hypocomplementemia is not uncommon in the course of chronic active hepatitis C infection. The triad of necrotizing vasculitis, chronic hepatitis C infection, and cryoglobulinemia occurs late after initial infection with hepatitis C. Antibodies to hepatitis C virus should be determined in a patient with necrotizing vasculitis, especially if liver function tests are elevated.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Daoud
authors.forename: R A
authors.initials: RA
authors.lastname: el-Azhary
authors.forename: L E
authors.initials: LE
authors.lastname: Gibson
authors.forename: M E
authors.initials: ME
authors.lastname: Lutz
authors.forename: S
authors.initials: S
authors.lastname: Daoud
mesh_terms: D000328:Adult; D000368:Aged; D003181:Complement C4 / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis; D003449:Cryoglobulinemia / Q000150:complications* / Q000276:immunology / Q000473:pathology; D005260:Female; D006526:Hepatitis C / Q000150:complications* / Q000276:immunology / Q000473:pathology; D018937:Hepatitis C Antibodies / Q000097:blood; D006521:Hepatitis, Chronic / Q000150:complications* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007868:Leg Dermatoses / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D011693:Purpura / Q000276:immunology / Q000473:pathology; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood; D017445:Skin Diseases, Vascular / Q000150:complications* / Q000276:immunology / Q000473:pathology; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000150:complications* / Q000276:immunology / Q000473:pathology
chemical_list: D003181:Complement C4; D018937:Hepatitis C Antibodies; D003165:Complement System Proteins; D012217:Rheumatoid Factor