Anaphylaxis induced by the carboxymethylcellulose component of injectable triamcinolone acetonide suspension (Kenalog).

Background: Allergic reactions to various corticosteroids are rare but have been reported previously.
Objective: We wished to determine the etiology of an anaphylactic reaction in a patient who had received intracutaneous Kenalog (triamcinolone acetonide).
Methods: Skin testing and serologic testing for allergen-specific IgE antibodies was performed for triamcinolone acetonide, its individual components, and three other corticosteroid preparations in both the patient and six other nonallergic persons.
Results: The patient had positive skin tests to only the carboxymethylcellulose component of triamcinolone acetonide. He had negative skin test reactions to three other steroid preparations which did not contain carboxymethylcellulose. Specific IgE antibodies to carboxymethylcellulose were also elevated by immunoassay and immunoblotting. Control patients had negative skin tests to triamcinolone acetonide, its components, and three other corticosteroid preparations, and their sera lacked significant specific IgE antibodies to these materials.
Conclusions: Our results indicate that the triamcinolone acetonide component responsible for the patient's reaction was the suspending agent carboxymethylcellulose. We urge physicians to consider component testing when patients experience allergic-type reactions to drugs.