Final answer:
The correctly spelled term is 'anaphylaxis', which refers to a severe systemic allergic reaction that can be life-threatening and requires immediate treatment with an epinephrine autoinjector in an emergency.
Step-by-step explanation:
The term that is spelled correctly is anaphylaxis, which is a systemic and potentially life-threatening type I hypersensitivity reaction. Anaphylaxis is also known as anaphylactic shock. It is a rapid response to allergens which can lead to severe symptoms such as a drop in blood pressure, changes in heart rate, shortness of breath, and swelling that could block the airways. Emergency treatment for anaphylaxis often involves an epinephrine autoinjector, like an EpiPen®, to help control the immune reaction.