IgE-mediated hypersensitivity reactions to methylprednisolone.

BACKGROUND

Allergic reactions to systemically administered corticosteroids seem to be infrequent considering their extensive use. The aim of the study was to evaluate the IgE response in patients with immediate allergic reactions to methylprednisolone (MP).

METHODS

Four subjects who developed immediate reactions after MP administration and ten controls with good tolerance to MP administration were evaluated. Skin prick and intradermal testing were done using MP, hydrocortisone (HC), and dexamethasone (DX). If negative, a drug provocation test (DPT) was done to confirm the diagnosis and assess cross-reactivity. The in vitro IgE response was evaluated by the basophil activation test (BAT) and ImmunoCAP.

RESULTS

Three patients were diagnosed by the presence of a positive skin test in the immediate reading with MP, two by prick and one by intradermal testing, and one patient was skin test negative and diagnosed by DPT. All four patients had good tolerance to HC and DX. The BAT was positive for just MP in those patients with positive skin tests, with all patients being negative for HC and DX. Two patients were also ImmunoCAP positive to MP.

CONCLUSIONS

This study confirms the existence of immediate allergic reactions to MP and that some are mediated by specific IgE antibodies. Skin testing, ImmunoCAP and the BAT are useful to confirm the diagnosis.