[History and physycal examination].

The most effective method for diagnosing food allergy is the clinical history, which includes anamnesis and physical examination. The anamnesis must include a directed and detailed questioning, and together with the physical examination, it will provide the necessary data to guide the diagnosis and suggest whether the pathophysiology is mediated or not by IgE, which is relevant for the selection and interpretation of the tests. specific and establish the accurate diagnosis, in addition to evaluating the possibility of distinguishing between the different differential diagnoses. It is important to assess the clinical history, because no in vivo or in vitro test is relevant if it is not confirmed with it. Even if there is a strong history of food allergy detected in the history, positive tests can confirm the diagnosis without the need for oral challenge, thus avoiding the risk and cost of performing it. The expression of food allergy is influenced by non-modifiable risk factors that include sex, race and genetics (familial), and modifiable factors: atopic dermatitis, vitamin D deficiency, diet high in polyunsaturated fats and deficient in antioxidants, consumption of antacid drugs, obesity, increased hygiene, influence of the microbiota, time and route of food exposure (increased risk by delaying oral ingestion of allergens and concomitant environmental exposure of the same that leads to sensitization and allergy).