title: Diagnostic evaluation of patients with nonimmediate cutaneous hypersensitivity reactions to iodinated contrast media.
abstract: BACKGROUND
  Nonimmediate hypersensitivity reactions to iodinated contrast media (CM) are common. Allergological evaluation is necessary to confirm the diagnosis and to find a tolerated alternative. The aim of this study was to establish the role of skin testing and the drug provocation test (DPT) in the diagnosis of nonimmediate reactions to CM.
  
  
  METHODS
  Skin intradermal testing and patch testing with delayed readings were carried out with different CM (iobitridol, iomeprol, iodixanol, iohexol, ioversol, iopramide and ioxaglate). Single-blind placebo-controlled DPT was carried out in those cases with a negative skin test. In seven cases, a skin biopsy was obtained from positive skin tests and positive DPT.
  
  
  RESULTS
  Of the 161 subjects evaluated, 34 (21.1%) were skin-test positive, 21 (50%) to Iomeprol, 7 (16.7%) to Iodixanol, 5 (11.9%) to Iobitridol, 4 (9.5%) to Ioxaglate, 3 (7.1%) to Iohexol and 1 (2.4%) to Iopramide. DPT was positive in 44 cases (34.6%) that were skin-test negative, 38 (76%) to Iodixanol, 8 (16%) to Iomeprol and 4 (8%) to Iohexol. Of 78 cases (48.4%) with confirmed hypersensitivity, 34 (43.6%) were identified by skin testing and 44 (56.4%) by DPT. Skin biopsies showed a perivascular mononuclear cell infiltrate, mainly in the dermis, with higher levels of CD4 than CD8 T lymphocytes, with expression of activation markers and skin homing receptors.
  
  
  CONCLUSIONS
  Patients with nonimmediate reactions to CM were identified by skin testing in 43.6% and by DPT in 56.4%. The method to confirm the diagnosis differed depending on the CM involved.
authors.affiliation: Allergy Service, Carlos Haya Hospital, Malaga, Spain. mjtorresj@gmail.com
authors.forename: M J
authors.initials: MJ
authors.lastname: Torres
authors.forename: F
authors.initials: F
authors.lastname: Gomez
authors.forename: I
authors.initials: I
authors.lastname: Doña
authors.forename: A
authors.initials: A
authors.lastname: Rosado
authors.forename: C
authors.initials: C
authors.lastname: Mayorga
authors.forename: I
authors.initials: I
authors.lastname: Garcia
authors.forename: N
authors.initials: N
authors.lastname: Blanca-Lopez
authors.forename: G
authors.initials: G
authors.lastname: Canto
authors.forename: M
authors.initials: M
authors.lastname: Blanca
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000633:toxicity*; D003875:Drug Eruptions / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000139:chemically induced* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000276:immunology / Q000473:pathology; D012882:Skin Tests; D014283:Triiodobenzoic Acids / Q000633:toxicity*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids