Mc. Lopezserrano et al., 2 CASES OF SPECIFIC ADVERSE REACTIONS TO SYSTEMIC CORTICOSTEROIDS, Journal of investigational allergology & clinical immunology, 6(5), 1996, pp. 324-327
Although true allergic reactions due to systemic corticosteroid therap
y are not frequent, they should be kept in mind since allergic reactio
ns to this kind of therapy are possible. We report two cases of specif
ic adverse reactions resulting from systemic corticosteroid therapy wh
ich were diagnosed by provocation tests. The corticosteroids involved
in each case were paramethasone and betamethasone, and methyl-predniso
lone in both of them. Additives and other corticosteroids were studied
by skin tests and challenges, with negative results. The structures o
f paramethasone and betamethasone are similar with a 16 carbon methyl
group in both, and with a fluoride in the alpha position of the 6 carb
on in paramethasone, and a fluoride in the beta position of the 9 carb
on and a 6 carbon methyl group in betamethasone. Methyl-prednisolone d
iffers from that of other corticosteroids in its 6 carbon methyl group
. We report two cases of specific adverse reactions caused by corticos
teroids. Positive challenge tests showed a possible immunologic hypers
ensitivity mechanism in both cases. The patients' reactions demonstrat
ed cross-reactivity between methyl-prednisolone and the corticosteroid
s having a 16 carbon methyl group, and fluoride or methyl radicals on
the 6 carbon.