Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain severe itching all over the body that occurs in sudden bouts or attacks can be most commonly due to anaphylactic reaction or allergic reaction to some unknown allergen and whenever you are exposed to it an attack of pruritis or itching occurs.. Some common cause of allergy can be poison ivy,washing powders,certain skin cosmetics, medicines while at times can be indicative of underlying diseases related to liver or kidney diseases, anaemia etc.. You should consult an Allergist and get evaluated and thorough clinical evaluation and allergic testing like RAST test, Patch test, food challenge test can be done to rule out the exact cause of allergic reaction and treatment can be planned accordingly.. An immunotherapy can be instilled against the allergen to reduce the severity of the symptoms.. As of now you can take anti allergics like Benadryl or levocetrizine for relief from itching.. Hope this information helps.. Thanks and regards. Dr. Honey Nandwani Arora.