title: Allergic reactions due to mizolastine.
abstract: BACKGROUND
  An IgE-mediated allergic reaction to an antihistamine sounds like a paradox and is rare.
  
  
  OBJECTIVE
  To describe 2 patients with anaphylaxis caused by mizolastine. In one patient, differential diagnosis from food allergy was necessary, whereas in the other patient, the history was clear.
  
  
  METHODS
  History and in vivo skin testing were used for diagnosis. A challenge test to mizolastine was also proposed, but both patients refused to give consent.
  
  
  RESULTS
  Skin test results were positive to mizolastine, whereas tests to the inert ingredients of the mizolastine tablets and to other H1 and H2 blockers had negative results.
  
  
  CONCLUSIONS
  In vivo tests are highly sensitive, and they confirmed the diagnosis of the uncommon antihistamine allergy.
authors.affiliation: Allergy and Clinical Immunology Outpatient Department, Social Insurance Institute, Thessaloniki, Greece.
authors.forename: Antonia
authors.initials: A
authors.lastname: Vythoulka
authors.forename: Constantinos
authors.initials: C
authors.lastname: Pitsios
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kompoti
mesh_terms: D000328:Adult; D000707:Anaphylaxis / Q000139:chemically induced*; D001562:Benzimidazoles / Q000009:adverse effects*; D003937:Diagnosis, Differential; D004342:Drug Hypersensitivity / Q000097:blood / Q000276:immunology / Q000503:physiopathology*; D005260:Female; D005512:Food Hypersensitivity; D006634:Histamine H1 Antagonists / Q000009:adverse effects*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008875:Middle Aged; D012882:Skin Tests
chemical_list: D001562:Benzimidazoles; D006634:Histamine H1 Antagonists; C076170:mizolastine; D007073:Immunoglobulin E