What do you mean by anaphylaxis?

Severe reaction: Anaphylaxis is a severe, life-threatening allergic reaction, usually to a defined trigger (insect sting, medication, food). The reaction usually affects multiple body systems and is characterized by multiple symptoms (cough, wheeze, shortness of breath, throat discomfort, swelling of the lips/tongue, nausea, vomiting, diarrhea, or hives).

Life-threatening rxn: Anaphylaxis is a life-threatening allergic reaction affecting several parts of the part simultaneously. Mast cells release histamine & other substances making blood vessels leaky. The plasma leaking out causes swelling in the skin (hives & angioedema) & windpipe (laryngospasm) as well as asthma, vomiting, gut pain. If enough plasma leaks out the patient may go into shock. Death may ensue.