A case of anaphylaxis is reported in the course of a prick by prick with Lupinus albus and roasted peanut in a 20-year-old woman. We focused on some main topics. First of all it seems important to underscore the potential risks connected to the practice of the prick-by-prick with fresh foods in allergic patients, especially when testing cross-reactive substances, such as White Lupine, peanuts, or soy. It is important that clinicians who perform prick tests be aware of the risk related with in vivo tests in allergic patients. Second, we discuss the problem of the hidden allergens, such as White Lupine flour, or soy flour which are utilized to improve wheat flour because of their lower cost. Patients with a demonstrated allergy to peanuts should be assessed for lupine allergy and informed about the "hidden allergens" issue. Finally, we believe that component resolved diagnosis, the serum specific IgE against molecular components, that is normally considered a second-level diagnostic step has an important role even as a first line approach at least in some selected cases.