title: Erythema nodosum-like eruption as a manifestation of azathioprine hypersensitivity in patients with inflammatory bowel disease.
abstract: BACKGROUND
  Clinical manifestations of hypersensitivity to azathioprine may mimic symptoms of the initial disease. We report 5 cases of peculiar skin hypersensitivity reactions to azathioprine in patients with inflammatory bowel disease.
  
  
  METHODS
  In 5 patients with a recent azathioprine regimen, manifestations appeared between 8 and 18 days after drug introduction. All patients had a high fever. Three patients initially had erythema nodosum; 2 patients had sterile pustules. All had elevated neutrophil counts and serum C-reactive protein levels, whereas eosinophil counts were normal, ruling out drug-induced rash with eosinophilia and systemic symptoms. In 3 patients who were rechallenged with azathioprine or with 6-mercaptopurine, dermatological lesions recurred within hours.
  
  
  CONCLUSIONS
  Erythema nodosum and pustules are rarely reported manifestations of azathioprine hypersensitivity. Both skin lesions may be related to the clinical activity of inflammatory bowel disease. Relapse of such lesions shortly after thiopurine rechallenge should raise the hypothesis of hypersensitivity rather than pharmacological manifestations.
authors.affiliation: Department of Dermatology, Hôpital Tenon, Université Pierre et Marie Curie, Paris, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: de Fonclare
authors.forename: Kiarash
authors.initials: K
authors.lastname: Khosrotehrani
authors.forename: Sélim
authors.initials: S
authors.lastname: Aractingi
authors.forename: Paul
authors.initials: P
authors.lastname: Duriez
authors.forename: Jacques
authors.initials: J
authors.lastname: Cosnes
authors.forename: Laurent
authors.initials: L
authors.lastname: Beaugerie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001379:Azathioprine / Q000008:administration & dosage / Q000009:adverse effects*; D003937:Diagnosis, Differential; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D004893:Erythema Nodosum / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged
chemical_list: D007166:Immunosuppressive Agents; D001379:Azathioprine