Hi,
The commonest causes of itchy rashes all over body area one or combination of the following:
Pollution related allergens through air contact, this can be in any form including pollens, fumes, dust, mites, the list is never ending once you get
allergy testing.
Internal allergens gone in through boods, beverages and the commonest are the preservatives.
You have already taken
Benedryl without any good output, hence I would advise you the following in such a situation:
Consult your Doctor as the lesion have increased.
Continue antihistamin.
Oral
steroids if antihistamin alone fails to resolve your problem.
Investigations of blood and treatment as per the findings.
Occasionally
Adrenaline may be required.
You have to observe very keenly for the instigating or enhancing factors and avoid these at any cost.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon