Immediate allergic reaction to thiocolchicoside confirmed by skin testing and basophil activation test: A case report and literature review

BACKGROUND: Thiocolchicoside is a muscle relaxant, anti-inflammatory, and analgesic. Administered orally, intramuscularly, or topically, this drug is used in the symptomatic treatment of muscular spasms and rheumatologic disorders. Despite its extensive use, thiocolchicoside is a very rare sensitizer.OBJECTIVE: To evaluate IgE-mediated reaction to thiocolchicoside by basophil activation test.METHODS: Allergological work-up with skin prick tests, intradermal tests and basophil activation test with thiocolchicoside.RESULTS: We report the first case of immediate reaction to thiocolchicoside confirmed by basophil activation test in addition to positive skin tests.CONCLUSIONS: BAT can be considered a complementary diagnostic tool to demonstrate an IgE-mediated reaction also for muscle relaxant drugs.