title: The cutaneous and systemic manifestations of azathioprine hypersensitivity syndrome.
abstract: BACKGROUND
  Azathioprine (AZA) hypersensitivity syndrome is a rare side effect that typically occurs early in the initiation of therapy and may include a cutaneous eruption. It is often under-recognized because it mimics infection or disease exacerbation. Until recently, the cutaneous findings associated with AZA hypersensitivity have been reported using nonspecific, descriptive terms without a supportive diagnostic biopsy.
  
  
  OBJECTIVE
  To characterize the cutaneous and histologic findings associated with AZA hypersensitivity syndrome.
  
  
  METHODS
  We conducted a retrospective analysis of two cases of AZA hypersensitivity syndrome and describe the cutaneous manifestations and histological findings of each case. A review of the English literature for cases of AZA hypersensitivity or allergic or adverse reactions associated with AZA was performed.
  
  
  RESULTS
  Sixty-seven cases of AZA hypersensitivity were reviewed; 49% (33/67) had cutaneous manifestations. Of those cases presenting with cutaneous findings, 76% (25/33) had biopsy results or clinical features consistent with a neutrophilic dermatosis, whereas the other 24% (8/33) were reported as a nonspecific cutaneous eruption.
  
  
  CONCLUSIONS
  Only case reports in which the skin findings could be classified were reviewed.
  
  
  CONCLUSIONS
  The predominant cutaneous reaction reported in the literature and observed in the present case series is a neutrophilic dermatosis. Hypersensitivity to AZA can manifest along a wide clinical spectrum from local neutrophilic disease to a systemic syndrome. Skin findings may be an important early clue to the diagnosis of AZA hypersensitivity and aid in prompt recognition and treatment of this potentially life-threatening adverse drug effect.
authors.affiliation: Department of Dermatology, San Antonio Military Medical Center, San Antonio, Texas, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Bidinger
authors.forename: Karen
authors.initials: K
authors.lastname: Sky
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Battafarano
authors.forename: J Scott
authors.initials: JS
authors.lastname: Henning
mesh_terms: D000328:Adult; D000368:Aged; D001379:Azathioprine / Q000009:adverse effects* / Q000627:therapeutic use; D001707:Biopsy, Needle; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D003875:Drug Eruptions / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016463:Sweet Syndrome / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology
chemical_list: D007166:Immunosuppressive Agents; D001379:Azathioprine