Final answer:
An acute allergic reaction can be treated in the prehospital setting using epinephrine injection and subsequent administration of antihistamines and corticosteroids.
Step-by-step explanation:
An acute allergic reaction, also known as anaphylaxis, can be treated in the prehospital setting using several approaches. The initial treatment involves administering an epinephrine injection, which helps counteract the drop in blood pressure and relaxes bronchial smooth muscles. Patients with known severe allergies often carry self-administering auto-injectors, such as EpiPen, to use in case of exposure to allergens. Follow-up treatment may include antihistamines and slow-acting corticosteroids to prevent potential late-phase reactions.