Treatment Algorithm for Adults with Anaphylaxis

Introduction:

Allergies is caused when the body overreacts to a harmless substance. Anaphylaxis is a severe form of allergy that is life-threatening. This allergic reaction is multi-systemic and is triggered by common harmless substances, such as foods, latex, medications, and insect stings. The anaphylaxis symptoms can occur within minutes or hours after exposure to the allergen (substance triggering the allergic reaction). Anaphylaxis can quickly affect the patient’s breathing, blood pressure, and heart and requires emergency care. Without quick medical intervention, these can be fatal.

What Are the Common Causes of Anaphylaxis?

Anaphylactic episodes may be caused by harmless common allergens, including the following;

• Food: Common foods such as fish, peanuts, tree nuts (such as cashews, almonds, pecans, and walnuts), milk, shellfish, and eggs are known to cause anaphylaxis.

• Insect Bites and Stings: Stings of hornets, wasps, fire ants, and other insects can cause anaphylaxis episodes.

• Medications: Drugs such as Penicillin are known to cause severe anaphylactic reactions. Common drugs such as pain relievers (such as Ibuprofen and Aspirin) and antibiotics can also trigger anaphylaxis. In addition, dyes used in medical scans and general anesthetics (medicines that put you to sleep during surgery or other invasive procedures) can cause anaphylaxis episodes.

• Other Allergens: Repeated exposure to allergens like latex increases the risk of anaphylactic episodes. People with previous mild episodes are at risk of developing severe allergic attacks. In rare cases, these can also occur without any triggers.

What Are the Symptoms of Anaphylaxis?

When a person comes in contact with the allergy-causing substance, the symptoms can start within a few minutes (five to 30 minutes) or may become noticeable later (after an hour or so). Anaphylaxis affects more than one body part, including the respiratory system and the heart. In severe cases, it can lead to the inability to breathe, shock, and heart failure. In addition, anaphylaxis can cause the following symptoms and signs:

• Swelling of the tongue.

• Swelling of the throat and airway.

• Breathing difficulty (caused by swelling of the throat and narrowing of the airway).

• Wheezing.

• Swelling of the face.

• Difficulty in swallowing.

• Coughing.

• Slurred speech.

• Confusion.

• Anxiety.

• Unusual breathing sounds.

• Itchiness and redness of the area affected, such as eyelids, lips, and skin.

• Hives and skin eruptions.

• Fluttering heart.

• Nausea and vomiting.

• Stomach cramps and diarrhea.

• Skin starts to appear blue, especially on the nail bed and lips.

• Fast and weak pulse.

• A marked drop in blood pressure.

• Dizziness or fainting.

• Unconsciousness.

How Are Anaphylactic Emergencies Treated?

The diagnosis is not obvious in anaphylaxis. The patient has to be immediately taken to the nearest emergency department if anaphylaxis is suspected. Anaphylaxis is most likely if the following three criteria are seen together in the patient:

• Sudden onset and rapid progression of the symptoms.
• Hives, itching, flushing, severe swelling, and other skin and mucosal changes.
• Life-threatening symptoms that affect breathing, airway, and blood flow following exposure to a trigger.

Prompt evaluation of the patient’s condition, monitoring, and treatment initiation can help save lives.

• The patient must be made to lie flat, and their legs should be kept elevated. The caregiver can administer the prescribed self-injectable Epinephrine if anaphylaxis is suspected. Immediate cardiopulmonary resuscitation must be performed if the patient has difficulty breathing, shock, or heart failure due to anaphylaxis (if trained). Call for immediate emergency help if you suspect the patient has life-threatening anaphylaxis-related issues.

• A trained and specialized doctor assesses the patient promptly and initiates Adrenaline administration immediately. Adrenaline is given intramuscularly (0.5 milliliters, 1:1000 Adrenaline) or through the vein. Only experienced specialists administer Epinephrine through the veins. Adrenaline is repeated if no improvement is seen after five minutes.

• The doctors managing anaphylaxis check the patient’s airway, breathing, circulation, disability, and exposure. If the allergic trigger is found, it is removed if possible.

• If cardiac arrest occurs following anaphylaxis, cardiopulmonary resuscitation, advanced life support, and intravenous Adrenaline administration is done immediately.

• Oxygen supplementation through masks and intubation (tubes inserted to help with breathing) is done whenever necessary. High-flow oxygen at the highest concentration possible is given rapidly.

• Fluid resuscitation is initiated if the blood pressure drops. Intravenous access is obtained to give the fluids directly into the blood. The rapid intravenous fluid challenge of 500 to 1000 ml is usually given to adults.

• Anti-allergy drugs and corticosteroids help to reduce the inflammatory response. Thus, after initial resuscitation, 10 mg of Chlorpheniramine and 200 mg of Hydrocortisone, intramuscular injection, or slow intravenous injection are given. These calm the patient’s overactive immune system and relieve symptoms.

• Pulse oximetry (blood oxygen level), electrocardiogram (heart rhythm and function), and blood pressure are continuously monitored to assess the patient.

• Blood tests (such as mast cell tryptase levels) are performed to confirm anaphylaxis and identify triggers, if unknown. The systemic complications due to anaphylaxis are assessed and managed accordingly.

• It is usual to keep the patient under observation in the hospital for six to 12 hours till the symptoms subside. During discharge, the patient is usually given medications for a few days to prevent the symptoms. The patients and their caregivers are educated about anaphylaxis and instructed on how to prevent such episodes in the future. Referral to specialist allergy clinics is also provided. The various steps that we can take to manage an anaphylactic emergency are highlighted in the algorithm below:

How to Prevent Anaphylaxis?

• It is vital to identify the possible triggers of the allergic attack.

• If a patient has had anaphylactic reactions, a visit to an expert doctor (immunologist or an allergist) is essential. The consultation will help identify the triggers and help develop an emergency plan to keep the patient safe.

• Avoid exposure to allergens that can cause anaphylaxis. If you have a known food or medication allergy, do not consume it.

• Caregivers, friends, and family members should be informed about the allergy-causing agents and how to deal with an anaphylactic episode.

• Always carry the prescribed auto-injectors (Epinephrine) to use in case of an allergic response.

Conclusion:

The body’s immune system can overreact to harmless substances and cause anaphylaxis. For example, food such as fish, nuts, or milk, insect bites, and certain medications can trigger anaphylactic episodes. Anaphylaxis causes breathing difficulty, lowers blood pressure, and can lead to shock and heart failure. It is life-threatening and requires immediate medical attention. The anaphylactic episodes can be managed successfully by the emergency medical team. A quick assessment, management of the airway, breathing, and circulation, and Epinephrine administration (intramuscular injection or through the veins) help patients survive. Oxygen therapy, fluid resuscitation, and other medications, such as anti-allergy drugs and steroids, are done to manage and treat anaphylaxis. Patients with a known risk of anaphylaxis should always carry prescribed self-injectable Epinephrine with them for use during an emergency. One must identify and avoid the triggering allergens to prevent future anaphylactic attacks.