Final answer:
The initial treatment for anaphylaxis is to administer epinephrine immediately, using an auto-injector like an EpiPen® if available, followed by seeking emergency medical help. Subsequent treatments may include antihistamines and corticosteroids.
Step-by-step explanation:
The first step in the treatment of anaphylaxis is to give epinephrine. This is the most critical and immediate action to counteract the severe allergic reaction. Epinephrine works by constricting blood vessels to increase blood pressure, relaxing smooth muscles in the lungs to improve breathing, modulating heart rate, and reducing swelling that may block airways. Individuals with known severe allergies often carry an EpiPen®, which is a self-administering auto-injector of epinephrine, for immediate use in case of an anaphylactic reaction. After administering epinephrine, it is essential to seek emergency medical care. Further treatment may include antihistamines and corticosteroids to control the immune response and prevent potential late-phase reactions.