Understanding Allergic Reactions and Anaphylaxis

Exam Tip: If a patient presents with symptoms in only one category (e.g., only skin hives), it may be a mild allergic reaction. If symptoms appear in two or more categories (e.g., hives and difficulty breathing), treat it as anaphylaxis.

Treatment and Medication

Managing an allergic reaction depends heavily on the severity of the symptoms.

Mild Reactions: Antihistamines

For milder, localized reactions, antihistamines are commonly used. These medications work by counteracting the effects of histamine in the body. These are typically administered by mouth.

Severe Reactions: Epinephrine

In the event of anaphylaxis, antihistamines are not sufficient because they do not address the systemic collapse of the circulatory or respiratory systems. Instead, epinephrine must be administered. Epinephrine is a drug that slows or stops the effects of anaphylaxis by constricting blood vessels and relaxing the muscles in the lungs.

The standard method of delivery is via an epinephrine auto-injector.

Dosage Guidelines

Dosage is critical and is determined by the patient's weight:

• Children (up to 30 kg): Typically $0.15\text{ mg}$
• Individuals over 30 kg: Typically $0.3\text{ mg}$

How to Administer an Auto-Injector

1. Prepare: Remove the safety cap from the device.

2. Position: Press the device firmly against the middle third of the outer thigh.

3. Inject: Hold the device in place until a "click" is heard.

4. Hold and Rub: Hold the injector in place for 5–10 seconds, then remove it and rub the injection site for 30 seconds to assist absorption.

5. Repeat if Necessary: If symptoms do not improve within 5 minutes, a second dose should be administered in the opposite leg.

Emergency Response Protocol

If you suspect someone is experiencing anaphylaxis, you must act quickly.

1. Activate EMS: Call 9-1-1 (or your local emergency number) immediately.

2. Provide Care: Guide the person through using their auto-injector if they are able, or administer it yourself if they are unresponsive.

3. Monitor: Provide reassurance and monitor the person for increasing distress or changes in breathing until professional medical help arrives.

Important: Even if the person seems to recover after using epinephrine, they must still be evaluated by medical professionals, as a "rebound" reaction can occur.

Prevention

The most effective way to manage allergies is to prevent exposure to known allergens.

• Avoidance: Identify triggers (such as specific foods, insect stings, or environmental factors) and strictly avoid them.
• Medical Identification: Individuals with chronic allergies should wear medical identification, such as a bracelet, necklace, or a digital ID on their smartphone. This ensures that if they become unresponsive, EMS personnel are immediately aware of their condition.

(Note: While the image above is a general icon, medical identification serves as a vital communication tool during emergencies.)