title: Clinical allergy. Managing generalized interferon-induced eruptions and the effectiveness of desensitization.
abstract: BACKGROUND
  We evaluated the value of skin tests and the efficacy of a 12-step desensitization protocol to pegylated interferon (IFN) in patients with generalized drug eruptions due to IFNs.
  
  
  METHODS
  A retrospective study (1998-2009) was followed by a cross-sectional clinical study conducted prospectively (2009-2011). All patients received a dermatological clinical examination and skin tests. Twelve-step IFN desensitization was proposed for patient with active hepatitis C and no alternative therapy.
  
  
  RESULTS
  Twenty-six patients (13 males, mean age, 53.5 years) had generalized reactions to IFNs; 21 were treated with IFN-α and 5 with IFN-β. Moreover, 21 patients had skin tests. Intradermal tests (IDTs) were positive after an average of 72 h. Cross-reactivity between peg-IFN-α2a and peg-IFN-α2b was observed in 5/10 cases in the prospective study. In 16 of 26 cases, IFN treatment was stopped. In 8 of 16 cases of diffuse eczematous drug eruption, treatment was continued. The corticosteroid and antihistamine were sufficient in 4/8 cases. In three other cases, topical tacrolimus was highly effective. In 3 of 16 cases in which treatment were stopped, patients underwent the early resumption of peg-IFN-α. These three patients had positive tests with peg-IFN-α2a and peg-IFN-α2b and successfully completed the tolerance induction protocol for peg-IFN-α2b. Tolerance induction involved a weekly dose of peg-IFN and a gradual increase in the recovery of an antiviral C. Clinical tolerance was excellent, and the patients' viral load C became negative.
  
  
  CONCLUSIONS
  Our study demonstrates the benefit of allergy testing in cases of generalized drug reactions to IFN, cross-reactivities in a single class of IFNs and the importance of delayed IDT reading. We report for the first time the effectiveness of 12-step desensitization with peg-IFN.
authors.affiliation: Dermatology Department, University Hospital of Nancy, Brabois Hospital, Vandoeuvre les Nancy, France.
authors.forename: C
authors.initials: C
authors.lastname: Poreaux
authors.forename: J-P
authors.initials: JP
authors.lastname: Bronowicki
authors.forename: M
authors.initials: M
authors.lastname: Debouverie
authors.forename: J-L
authors.initials: JL
authors.lastname: Schmutz
authors.forename: J
authors.initials: J
authors.lastname: Waton
authors.forename: A
authors.initials: A
authors.lastname: Barbaud
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D003888:Desensitization, Immunologic / Q000379:methods; D003875:Drug Eruptions / Q000175:diagnosis* / Q000628:therapy*; D005260:Female; D006801:Humans; D007372:Interferons / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D007372:Interferons
keywords: cutaneous adverse drug reaction; drug allergy; interferon; skin tests; tolerance induction