[Toxicoderma caused by prednisone and prednisolone. Value of skin tests in the screening of cross sensitivity].

INTRODUCTION

Allergic reactions to general corticosteroid therapy are uncommon.

CASE REPORT

We report a patient with systemic lupus erythematousus who developed skin rash after initiation of prednisone then prednisolone therapy. Histology evidence suggested leukocytoclastic vasculitis. The skin tests (prick tests, intradermoreactions and patch-tests) using a battery of injectable corticosteroids showed a highly positive reaction to prednisolone, methylprednisolone and dexamethasone on the intradermo-reactions 24 hours later. Histology examination of a positive-response showed leukocytoclastic vasculitis associated with eczematiform alterations of the epidermis compatible with a drug reaction. The skin tests however were negative for betamethasone, triamcinolone, paramethasone and hydrocorticose. The patient was treated with betamethasone and no skin reaction was observed.

DISCUSSION

Skin tests, particularly intradermo-reactions read 24 hours later would appear to be useful in identifying possible cross-sensitivity.