Cutaneous adverse drug reaction induced by oral dexamethasone with possible cross-reactivity to Group 1 corticosteroids confirmed by patch testing and intradermal testing.

Whereas a recent large study from Europe reported that 1.2% of patch tested patients have corticosteroid contact hypersensitivity,(1) cutaneous adverse drug reactions (CADRs) caused by systemic corticosteroids are less well described.(2) Coopman et al originally defined four classes of corticosteroids according to their structure (A, B, C, and D)(3); however, a recent simplified classification system proposed by Baeck and Goossens has refined this further into three different groups (1, 2, and 3).(4) Cross-reactivity does not always follow this categorization. Here, we report a novel case of a CADR induced by oral dexamethasone with possible cross-reactivity to Group 1 corticosteroids.