strange allergies

Last Nov 2005 my then 26 year old daughter began having a terrible red rash on the front of her body almost like sunburn. Seven month with the dermatologist left us with no answer.  Allergist tested and she's allergic to all weeds, trees, grasses (she has cut the grass for years) and some foods. Allergy shots are helping some but her hands are so rashed and cracked that I wouldn't shake hands with her.  Could this be a reaction to the Thimerosal in a flu shot given in Oct?  She was also on prednisone 3 times because it was so bad.  There is no manifestation of inside problems, just skin condition. Anybody have any ideas? Used non soaps, prescriptions, special lotions, Theraseal.  It looks like there is no moisture in her hands.

[AMA17]

did she quit eating the foods she was allergic too?  My co-worker cannot eat vitamin C (orange, tomatoes, etc etc) or her hands become all red & cracked.