What is the cause and remedy for itchy rashes all over the body?

Q: Ten days ago I had a major allergy in my body, especially after 8 PM. I had big rashes and itching all over my body till next morning 9 AM. I thought its food allergy so I stopped taking food from outside. I only take roti, dal and water (8-15 glasses per day). I am taking homeopathic medicines for the past 3 days. What is the problem? My family doctor suggested a bio-combination tablets ferrum phosphoricum and natrum sulphuricum. I am taking this also.

A:A food allergy rash is unlikely to go on for so long. It sounds as if you have acute urticaria, which is sometimes a temporary (up to six weeks) response to a viral infection. It can also occur with intestinal parasites, or be associated with other illnesses. I wouldn't expect changing your diet to be the answer, and antihistamines are usually effective in preventing the rash or at least relieving the itching. Chronic, (i.e. more than six weeks duration), urticaria which has no known underlying cause is known as idiopathic and can take up to three years to disappear spontaneously. More than half of all chronic urticaria is idiopathic.