September 18, 2012
It’s not always easy to identify the cause of itchy skin. Sometimes itching or a rash can be caused by a new cosmetic or skin care product. But often it’s the result of a food allergy. So when patients come in with itchy skin or rashes, I ask them about their medications, supplements, and diet. If there doesn't seem to be an obvious cause, I'll often ask them to keep a food diary, including vitamins, herbs, sodas, snacks, and illicit drugs. (Why illicit drugs? I know of someone who traced his rash to the pesticides used on the marijuana he smoked. You never know.)
Itching can be triggered or worsened by histamine, which is why antihistamines like Benadryl and Claritin can help relieve it. However, many antihistamines can cause drowsiness, and an antihistamine won’t solve the problem if the cause of your itching is something you ate. Avoid these foods if you have hives or other itchy rashes:
Foods that are high in histamine (especially fermented and pickled foods): tofu; soy sauce; aged cheese (blue or Parmesan); canned or smoked fish; sausage and salami; champagne, beer, and wine; sauerkraut; vinegar and mayo.
Foods that stimulate your body to release histamine: egg whites, citrus fruits, strawberries, chocolate, shellfish, milk, nuts, aspirin, ibuprofen (Advil, Motrin).
For more information on what to eat and what to avoid when you have an itchy rash, check out Chapter Five of Feed Your Face.