title: Patch testing with serial dilutions of budesonide, its R and S diastereomers, and potentially cross-reacting substances.
abstract: BACKGROUND
  Budesonide, a marker for corticosteroid allergy, is a 1:1 mixture of 2 diastereomers, the R and S, present in all commercial formulations. Budesonide is said to cross-react with group B substances through the R and S diastereomer and some group D substances only through the S diastereomer.
  
  
  OBJECTIVE
  To investigate the cross-reactivity pattern between the R and S diastereomers and 4 potentially cross-reacting substances, 2 from group B and 2 from group D.
  
  
  METHODS
  By patch testing 10 patients hypersensitive to budesonide with a serial dilution of budesonide, the R and S diastereomer, triamcinolone acetonide, amcinonide, prednicarbate, and hydrocortisone-17-butyrate.
  
  
  RESULTS
  Nine of 10 patients reacted to budesonide and the S diastereomer. Seven of 9 to the R diastereomer. Each of the 9 patients with S diastereomer allergy reacted to the group B and/or group D substances. Five patients reacted to triamcinolone acetonide, not to 1.0% but only to 0.0010% and 0.00010%.
  
  
  CONCLUSIONS
  The R and S diastereomers can induce positive patch test reactions in budesonide-hypersensitive individuals. The potential of budesonide to cross-react with substances from group B and D might be explained by the presence of the 2 diastereomers. When patch testing with triamcinolone acetonide, much lower concentrations than recommended should be used.
authors.affiliation: Department of Occupational and Environmental Dermatology, Malmö University Hospital, Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Isaksson
authors.forename: M
authors.initials: M
authors.lastname: Bruze
authors.forename: J P
authors.initials: JP
authors.lastname: Lepoittevin
authors.forename: A
authors.initials: A
authors.lastname: Goossens
mesh_terms: D000485:Allergens / Q000008:administration & dosage / Q000009:adverse effects* / Q000737:chemistry; D019819:Budesonide / Q000008:administration & dosage / Q000009:adverse effects* / Q000737:chemistry; D003429:Cross Reactions; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010328:Patch Tests / Q000379:methods; D013237:Stereoisomerism
chemical_list: D000485:Allergens; D019819:Budesonide