While my most recent hypothesis paper on the origins of IgE is still under review, I discovered a new study in Immunity that says in a nut shell

A growing body of evidence indicates that IgE antibodies and mast cells might serve not only as the effectors of immediate hy-persensitivity in subjects with established sensitivity but also as amplifiers during initial antigen exposure in naive subjects, potentially providing early signals for nascent Th2 cell and anti-body responses.

This fits perfectly to what I am saying , that there seem are self-enforcing & uncontrolled loops of a largely abandoned immune function.