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Fixed drug eruption due to loratadine
C H Pionetti1, M C Kien, A Alonso
1Centro de Alergia, Hospital de Clínicas, Buenos Aires, Argentina. alehclin@fmed.uba.ar
Allergologia Et Immunopathologia
|October 24, 2003
Summary
A fixed drug reaction (FDR) was diagnosed in an 8-year-old boy following oral loratadine intake. The ultra-brief challenge test and skin biopsy confirmed loratadine as the cause.
Area of Science:
- Clinical immunology
- Dermatology
- Allergy
Background:
- Fixed drug reactions (FDRs) are localized, recurrent cutaneous drug hypersensitivities.
- Loratadine, a second-generation antihistamine, is commonly used for allergic rhinitis.
Observation:
- An 8-year-old atopic boy with allergic rhinitis and asthma developed a well-defined erythematous and oedematous plaque on his elbow after taking oral loratadine.
- The lesion resolved spontaneously within a week without intervention.
Findings:
- The ultra-brief challenge test (UBCT) and skin histopathology were crucial in diagnosing loratadine-induced fixed drug reaction.
- Patch tests and control challenges with other antihistamines (ebastine, cetirizine) and excipients were negative.
- Conventional skin tests were deemed unsuitable for diagnosing this FDR.
Implications:
- This case highlights loratadine as a potential trigger for fixed drug reactions.
- Emphasizes the diagnostic utility of the UBCT and skin biopsy in suspected FDRs.
- Informs clinical practice regarding antihistamine-induced hypersensitivity reactions.