ABSTRACT
Introduction (contexte de la recherche): IgE-mediated reactions to systemic corticosteroids (CSs) are rare. Hydrocortisone and methylprednisolone succinate ester are the most frequent elicitors. Excipients of depot corticosteroids (like carmellose or macrogol) may also be involved. The involvement of the dipropionate form of betamethasone (present in the depot Diprostene) has not been studied. Objectif: To describe the case of a 40-year-old woman, who presented an anaphylactic shock reaction upon intra-articular administration of Diprostene (Betamethasone sodium phosphate and betamethasone dipropionate), associated with an iodinated radiocontrast media (ICM, Xenetix). Methodes: An allergy work-up was performed, according to recommendations for severe immediate reactions. Nine months after the reaction [hypotension (7/5 mmHg), erythema and desaturation at 94%, treated with adrenalin, methylprednisolone hemisuccinate, dexchlorpheniramine] the patient underwent skin prick tests (SPT) and intradermal tests (IDT) with ICM, bethamethasone and Diprostene (commercial molecules). Latex and chlorexidine were also studied. Resultats: The tests resulted negative for ICM, latex and chlorexidine (including serum specific IgE ImmunoCAP ThermoFisher Scientific), bethametasone phosphate (IDT 0.4 mg/mL) and carmellose (IDT 0.5 mg/mL). SPT elicited a positive reaction towards Diprostene in immediate reading, (for 5, 0.5, 0.05 mg/mL) with an erythema (10, 8, 5 mm respectively) and a wheal (of at least 3 mm for each SPT). We performed an oral drug challenge to bethametasone phosphate for a total of 8 mg and it was well tolerated. The basal tryptase was 5.5 microg/mL. Tryptasemia 30 minutes after the reaction was 26.8 microg/mL. Conclusion(s): We describe an anaphylactic reaction to Diprostene, proven by positive ST. The hypothesis of allergy to betamethasone dipropionate is under investigation. The hypothesis of allergy to macrogol, the other excipient of (which was not tested separately) is less likely, since the patient received Commirnaty SARS-CoV-2 vaccine 3 months after the reaction. The allergy work-up is ongoing (tests are programmed for betamethasone dipropionate alone).Copyright © 2023