A 42-year-old female presented with a sudden onset facial edema, dyspnea, and urticaria. A detailed history revealed that she had ingested half a teaspoon of flaxseed flour, about an hour before her symptoms appeared.

Although, a skin prick test for heated flaxseed flour extract showed negative responses, an intradermal test showed positive result, hinting towards an Immunoglobulin E-mediated reaction.

How should this patient be treated?