Food allergies are not likely to cause a runny nose. They usually cause scratchy, itchy mouth and throat; or you may develop hives, a skin rash, nausea, vomiting, diarrhea, or stomach cramps, or have difficulty breathing. Some older individuals experience a runny nose when they eat spicy, hot foods. That's called gustatory rhinitis, and the quickest cure is to finish eating or order something else.