Published online: February 3, 2018
True corticosteroid (CS) allergy is often over-diagnosed and many patients are instead allergic to excipients found in various CS preparations. Excipient testing is frequently neglected and may lead to unnecessary drug avoidance or dangerous re-exposure.
Li et al. published their study on the clinical characteristics and frequency of excipient allergy in patients with confirmed allergy to CS preparations in The Journal of Allergy and Clinical Immunology: In Practice. They present the largest published cohort of patients with suspected CS allergy investigated with drug provocation testing (DPT) and propose a comprehensive diagnostic algorithm with a focus on excipient testing.
True allergy to CS preparations was rare (confirmed in only 14%) and the majority of confirmed cases were actually allergic to excipients. Patients with respiratory manifestations were significantly more likely to be truly allergic. Carmellose eye drops served as a readily available source of carboxymethylcellulose for excipient testing.
CS allergy may be over-diagnosed without excipient testing. Increased physician vigilance and the use of a comprehensive diagnostic algorithm may be useful to facilitate accurate diagnosis and optimize patient management.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.