Molecules from one group differ sufficiently from other groups to explain the lack of cross-reactions among groups A, B & D. However, Budesonide which belongs to Group B is well known to cross-react with Group D steroids . Therefore, Budesonide is a marker for Group B and some of Group D steroids, like hydrocortisone butyrate (locoid). Molecular structure is not the whole story since cross-reaction patterns differ from patient to patient. Also, because of metabolism and degradation, several different molecules can be formed, resulting from reactions from the degradation product and not the parent compound. Because of the difficulty of predicting cross reactions, when hypersensitivity to one steroid is demonstrated all the steroids available in New Zealand should be tested, in order to recommend a valid alternative.
Steroids are naturally occurring substances that are produced in our bodies to regulate growth and immune function. There are many different kinds of steroids, including “anabolic steroids” such as testosterone and “female hormones” such as estrogen , and corticosteroids such as cortisol, which is produced by the adrenal glands. Corticosteroids are the type of steroid used for eczema. Corticosteroids have many functions in the body, but among other things, they are very effective at controlling inflammation. The way corticosteroids reduce inflammation is very complicated, but it involves temporarily altering the function of a number of cells and chemicals in the skin.