What Causes All Body Itching With Swollen Blisters On Penis?

please help it seems caused by allergies penis and all the body itching and swelling little blisters swollen penis itchy why trying to sleep all over body fills great to put under hot water but don t because get more and bigger blisters. just recently became allergic 2 tomatoes avocados and garlic/ latex whant to eat normal again have had the problem for 2 years goto doctors in they give me a shot of steroids but never fix the allergy problems