Food Allergies: Symptoms Make an Appointment Refer a Patient Ask a Question Reviewed by Bruce J. Lanser, MD, MPH (August 01, 2015) Food allergies may cause many different allergy symptoms. Allergic reactions to food usually occur rapidly after eating the offensive food, usually within 30 minutes and almost always within 2 hours of ingestion. Signs and symptoms of food allergy can involve the nose, mouth, stomach, skin, lungs and heart. Skin Symptoms: Include itching, flushing (redness), hives and swelling. Oral/Stomach Symptoms: Include itching, tingling, burning, abdominal cramping, nausea, vomiting and diarrhea. Respiratory Symptoms: Include nasal congestion, runny nose, sneezing, throat swelling, wheezing and/or difficulty breathing. Life-threatening, anaphylactic reactions: Include loss of consciousness and stopped breathing. Call 911 immediately if you suspect anaphylaxis. Cardiovascular Symptoms: Include lightheadedness, fainting, low blood pressure and shock. Reduce Exposure to Food Allergies Seafood Allergy 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.