Allergic reactions due to mizolastine.
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.
Vythoulka
Antonia
A
Allergy and Clinical Immunology Outpatient Department, Social Insurance Institute, Thessaloniki, Greece.
Pitsios
Constantinos
C
Kompoti
Evangelia
E
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
D001562:Benzimidazoles; D006634:Histamine H1 Antagonists; C076170:mizolastine; D007073:Immunoglobulin E