[History-taking of the allergic patient].

Etiological diagnosis of an allergic condition is assured mostly clinically and in particular by the data from a specific and minute interrogation. Complementary investigations only confirm the diagnostic suspicion produced by this interrogation, which includes several essential steps: The history of the patient from the first symptom to the day of consultation. The common criteria of unity of time, place or action on the different manifestations of hypersensitivity. The provocation factors and improvement of critical episodes. The mode of life of the subject and the factors of environmental imbalance.