Allergic reactions can cause by several aliments and foods. Symptoms usually appear after ingestion, several hours after consumption or even almost immediately. Various food allergies can lead to serious diseases and in some cases to death, so the priority for people suffering from them should be prevention and completely avoiding foods that cause this kind of reactions. Allergy to Alioidea is one of the probable causes of contact dermatitis, gingival and oculonasal diseases and asthma. In this review, we will focus on the increasing incidence of allergy to foods of common use like onions and garlic. In the last ten years, the world production of onions and garlic has increased of at least 25%. People make large use of them, not only in cookery but also from a therapeutic point of view. Their growing use is producing more and more specific, insidious and sometimes serious medical conditions, which highly influence the quality of life of patients. Medical practitioners should be able to recognize immediately these disorders in order to diagnose them quickly and accurately, avoiding unnecessary tests and treatments. We will also describe new patents for detecting food allergens.