Two patient profiles with probably different areas of immune recognition are identified as follows: the profile 1 patients were allergic to the frequently positively reacting cluster 1 only, for whom electrostatic fields (molecular charge) seem important; the profile 2 patients reacted to clusters 1 and 2 and/or 3, for whom steric fields (structure) are determinant and who probably presented a global recognition of the corticosteroid skeleton. A modified classification is thus proposed.

Background: Corticosteroids may cause immediate or delayed hypersensitivity. In 1989, based on structural and clinical characteristics, we put forward a classification of corticosteroids into four crossreacting groups, namely group A, B, C, and D, the latter later subdivided into two subgroups, i.e. D1 and D2. The constituents on the D-ring of the corticosteroid-molecule are considered to have a central role for binding to skin proteins and for cross-reactions patterns; however, halogenation of the molecules is also interfering.