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Updated: May 24, 2026
07:22
Basophil Activation Test for Allergy Diagnosis
Published on: May 31, 2021
Fexofenadine-induced urticaria
Sang Woo Lee1, Ji Yeon Byun, You Won Choi
1Department of Dermatology, School of Medicine, Ewha Womans University, Seoul, Korea.
Annals of Dermatology
|February 21, 2012
Summary
Fexofenadine, a common allergy medication, can paradoxically cause hives (urticaria) in rare instances. This case highlights the importance of considering drug-induced reactions even with widely used antihistamines.
Area of Science:
- Clinical immunology and pharmacology
- Adverse drug reactions
Background:
- Fexofenadine is a widely prescribed second-generation H1-antihistamine for allergic conditions.
- Antihistamines are generally considered safe, but rare adverse effects can occur.
Observation:
- A patient developed urticaria, a form of hives.
- The urticaria was suspected to be a reaction to fexofenadine (Allegra® 180).
Findings:
- Fexofenadine-induced urticaria was confirmed through a series of diagnostic tests.
- Diagnostic methods included a prick test, oral provocation test, and flow cytometry-assisted basophil activation test.
- These tests specifically identified fexofenadine as the causative agent.
Implications:
- This case underscores the potential for fexofenadine to induce urticaria, despite its common use.
- Clinicians should consider drug-induced urticaria in the differential diagnosis of allergic reactions.
- Advanced diagnostic techniques can help confirm rare drug hypersensitivities.
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