Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain the symptoms of intense itching all over my body  that comes and goes and is happening almost every day with raised bumps over the skin with no history of changing any products and foods can be due to causes like Hair 
follicle infection of 
folliculitis, 
allergic reaction to any food or medication or surface contact with any allergens like Poison ivy..
It can also be due to 
Mite Infestation causing Scabies..
Vistaril is an anti-allergic and will work by relieving the immediate symptoms of itching but will not resolve the underlying problem..
I would suggest you to consult an Allergist and get evaluated and a thorough clinical evaluation and investigations like blood tests and microscopic examination of the scrapings from bumps can help in diagnosis and treatment can be done accordingly..
In case if it is an allergic reaction anti allergics like Allegra or benadryl, steroids and also injection of steroid for faster resolution along with steroid ointment and cool compresses over red bumps can help..
In case of folliculitis antibiotics orally and oral and 
topical antibiotic and steroid 
ointments can be advised..
In case of Scabies oral 
Ivermectin and topical Premethrin lotion can help in relief..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.