RESUMO
The allergic to sunflower [Helianthus annuus] of the composite family is a rare, however, 13 cases of IgE-mediated anaphylactic reactions have been reported. It is most often generalized immediate reaction, with a total tolerance to the sunflower oil. This allergy manifests itself polymorphic and responds to all possible routes of exposure: ingestion, inhalation or contact. This is a boy of 18 years, followed for assessment of acute urticaria [4 episodes in 1 year]. The questioning is the notion of eating sunflower seeds before the symptoms. Skin tests were negative for aeroallergens and positive currents to extract seeds and sunflower oil. Specific IgE were increased. Allergy to sunflower seeds was used. The patient progressed well with conservative treatment [corticosteroids and oral antihistamine] with the eviction action. Through this observation, we emphasize the rarity of this form of allergy, the difficulty of the diagnostic investigation with an explanation of the pathophysiological mechanism