Hello, It is unlikely this chronic process is being affected by foods, i.e., food allergy. You can most certainly test for this, however, by blood tests (speciic IgE to common food panel that contains peanut, milk, wheat, soya, egg etc; or ask your doctor to test for the specific foods you think you may be allergic to). Skin tests also help determine allergies to foods although you should stop taking antihistamines or setroids (if you are on any) before this test. Medications do NOT affect blood results, only skin tests. Best Wishes.