thanks for your patience.
you seem to be having urticaria. its also called hives.
its a condition where there are red raised lesions all over the body with lot of itching.
these lesions are of various sizes and shapes and they come and go on their own. they need prompt treatment.
urticaria may be idiopathic or may have a variety of causative factors, there is a n exhaustive list available but to tell you the truth its really difficult to pin point one thing.
it can be due to food, insect bites, infection, medications, dust, pollen, animal dander, absolutely anything.
the best thing to do is to start prompt treatment for immediate relief.
tablet Allegra 180 mg orally once a day is the medicine I would recommend for atleast a couple of weeks. you may also need to extend it for 3 months to get the allergic response under control.
also you can apply cortisone lotion on the rash to soothe it. twice a day for 2 weeks.
avoiding fish, milk, nuts for 15 days would be a good idea and see if it further helps you.
it actually varies from person to person. it may or may not be related to food. you could in fact maintain a food diary and note down all that you have eaten in the last 24 hours whenever you get a rash. you will yourself see a pattern if its food related.
please feel free to ask me in case you have any queries.
Hope my recommendations are helpful.