Tom is a 19-year-old male, who presents with sudden onset of…

Tom is a 19-year-old male, who presents with sudden onset of edema of the lips and face and a sensation of throat tightness and shortness of breath” after a bee sting.  Physical exam reveals inspiratory and expiratory wheezing. Blood pressure is 78/44 mm Hg and heart rate is 102 bpm; respiratory rate is 24 /min. His clinical presentation is most consistent with the diagnosis of: