Have allergy to certain foods n dust.if i eat the one which triggers causes my skin to itch very badly and thn i have all red patches due to itching ?

Avoid these: If you suspect food allergy, or if foods cause skin rash, hives, or itching within 2 hours of ingestion (especially if this occurs consistently); then that food should be strictly avoided. See an allergist to confirm and/or characterize the nature of the allergy. Dust allergy is interestingly associated with certain food allergies.

Allergy: These symptoms clearly indicate allergy and these foods should be voided as much as possible. Every time someone is exposed to an allergen reaction is usually worse than the previous one.

Allergy to food: Allergy would be triggered every time you get exposed to anything you are allergic to. Its best to avoid those foods. If you develop rashes you can take antihistamines but if developing shortness of breath , tight chest, tight throat or rashes are spreading then please see doctor immediately .