In the case of a severe allergic reaction, what should be administered if available?

In the event of a severe allergic reaction, commonly referred to as anaphylaxis, the administration of an epinephrine auto-injector is critical. Epinephrine works quickly to counteract the life-threatening symptoms associated with anaphylaxis by narrowing blood vessels, which increases blood pressure, and relaxing the muscles in the airways to improve breathing. It also reduces hives and swelling, alleviating the symptoms of the allergic reaction.

While antihistamines, steroids, and oxygen may be part of the treatment plan for allergic reactions, they are not primary interventions for anaphylaxis. Antihistamines can help manage mild to moderate allergic reactions, but they do not act quickly enough to treat severe symptoms. Steroids can be used for their anti-inflammatory effects, but they take time to work and are not immediate solutions. Oxygen may be necessary if the individual is experiencing respiratory distress, but it does not address the underlying cause of anaphylaxis directly. Therefore, the immediate use of an epinephrine auto-injector is the most effective and essential action to take in response to severe allergic reactions.