I have been dtoxing my system and my lower back and calfs have become
painfully itchy, is this a sign of the toxins being forced out of my
body at these points or is it an allergic reaction to what I am
takeing ???

Please be more specific about what you have been doing in this detox
program.  Please be as specific as possible about what you are
taking/doing.

If, by "dtoxing my system," you mean "taking strong laxatives and
diuretics," it is quite possible that you have dehydrated yourself and
put your electrolytes out of balance. This is a common side-effect of
so-called "detoxifying" programs.