Allergic Reactions Overview
The immune system is our body’s defense mechanism against foreign materials (antigens). It uses white blood cells (cell-mediated immunity) and proteins in the blood called antibodies (humoral immunity) to attack the invaders. White blood cells, also known as T lymphocytes, or T-cells, organize the immune system’s fight against infection and directly attack the antigens.
Antibodies, which include Immunoglobulin A, D, G, M and E, protect the respiratory and gastrointestinal systems. An allergen is an antigen that produces an allergic reaction.
An allergy is an overreaction of your body’s immune system to a substance (allergen). Approximately 50 million Americans suffer from allergies. When a person comes in contact with an allergen, the body releases a massive amount of histamine, a chemical that causes allergy symptoms.
More severe allergic reactions may occur depending on the amount of exposure and the sensitivity to the allergen. Allergic reactions tend to get worse with each subsequent occurrence. The quicker the onset of symptoms, the more severe the reaction.
Allergic reactions can cause the following conditions:
Allergic rhinitis: Sneezing, nasal congestion, coughing
Asthma: A more serious condition that causes wheezing and shortness of breath due to narrowing of the airways and increased mucus production.
Skin allergies: Rashes, oozing blisters, hives (red raised lesions with itching and swelling) and contact dermatitis (poison ivy).
The most severe result of an allergic reaction, causing swelling in the airways and a sudden drop in blood pressure. Anaphylactic shock is life threatening, and requires immediate emergency medical care. Death can occur within minutes.
A person should never self-administer antibiotics prescribed for a friend or family member due to possible allergic reactions.
Allergens can be inhaled, swallowed, or simply come in contact with the skin. Common allergens include pollen, mold spores, household dust, pet dander, dust mites, insect sting venom, shellfish, dairy products, drugs, eggs, chocolate, nuts and poisons.
Although allergies to any antigen can result in anaphylaxis, peanuts, bee sting venom and penicillin can often cause a life-threatening reaction in highly allergic people.
Food is the leading cause of anaphylaxis in the community. There are about 30,000 food-induced anaphylactic reactions treated in the emergency department each year in the U.S. As many as 200 people die each year from anaphylaxis. When signs and symptoms involve more than one body system (respiratory, cardiovascular, skin, gastrointestinal), suspect anaphylaxis.
Signs and Symptoms:
*Hives, rashes, itchy skin
*Swollen face, eyes, throat, tongue
*Sneezing, difficulty breathing, coughing, congestion
*Stomach cramps, vomiting and diarrhea
*Dizzy, confused, agitated or anxious
*Flushed or pale skin
*Tightness in the chest and throat
1. Assess response, breathing, circulation and appearance.
2. Activate EMS (call 9-1-1).
3. Assist the victim with use of his or her epinephrine auto-injector if the victim requests help, you are trained and your state and workplace allow it.
4. Reassure the victim.
5. If allergic reaction is from a bee sting, quickly scrape off stinger with a straight-edged object.
People with known allergies may carry an epinephrine kit. Epinephrine is the most commonly used drug for emergency treatment of anaphylaxis (severe allergic reaction), because it quickly relaxes smooth muscles in the lungs to ease breathing, constricts blood vessels and stimulates the heartbeat to maintain blood pressure, and reverses swelling around the face and lips.
The sooner it is given, the more effective it is in stopping the reaction. Look for medical alert tags.
The EpiPen Auto-Injector is an example of a disposable drug delivery system prescribed by a physician and carried by people who have the potential for fatal allergic reactions.
The EpiPen contains a concealed needle that a victim can use to self-administer epinephrine for emergency treatment of a severe allergic reaction. It can be used through clothing or on bare skin. Parents and caregivers of at-risk children should be trained in its use.
Using an epinephrine auto-injector:
1. Carefully remove cap and press firmly against the thigh; hold for 10 seconds. Handle carefully.
2. Rub the injection site for about 10 seconds.
3. Go to the nearest hospital emergency department for further care and auto injector disposal.