The presence of specific IgE must be suspected not only because of the types of symptoms (itching, angioedema, dizziness and possible hypotension, as indicated by the visual disturbances, and their occurrence within one hour of administration) but also because the skin tests at immediate reading were strongly positive, as was the prick test, which is less sensitive than the intra-dermal test. The gene discussed is IGHE; the disease is angioedema.