Food Allergies: Diagnosis Make an Appointment Refer a Patient Ask a Question Reviewed by Dr. Lanser, Bruce J. Lanser, MD, MPH (July 31, 2015) Every diagnosis begins with a detailed medical history and physical examination. The doctor will ask many questions about the nature of the reaction, where and when it occurs, which foods are thought to cause symptoms, etc. You may be asked to keep a detailed food diary to help in making the diagnosis. Since the possibility to become allergic is inherited, expect some questions about other family members who may be allergic. Depending upon the findings of the initial evaluation, the following tests may be necessary: Allergy skin testing may be performed to check for sensitivity to selected food allergens. Blood testing is often indicated. A food diary may be necessary to record what was eaten, when it was eaten, how long after eating a reaction occurred, what was the reaction and what treatment was given. Food challenges, which are done with safety as the highest priority, may be performed as well. Learn reasons to do food challenges. Food Allergies & School Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.