Anaphylaxis
Anaphylaxis: Recognition, Clinical Presentation and Immediate Management
Anaphylaxis is an acute, systemic, and potentially life-threatening allergic reaction. It typically occurs within minutes to a few hours after exposure to the responsible allergen, with symptoms progressing rapidly. Early recognition of symptoms and immediate treatment are crucial for protecting the patient.
Clinical Presentation
The symptoms of anaphylaxis may involve multiple organ systems, most commonly:
- Skin: Itching, generalized rash (urticaria/hives), and angioedema (swelling of the lips, tongue, or eyelids).
- Respiratory system: A sensation of choking or throat tightness, shortness of breath, hoarseness, laryngeal swelling, and wheezing.
- Cardiovascular system: Sudden dizziness, severe weakness, a rapid drop in blood pressure, and possible loss of consciousness.
- Gastrointestinal system: Severe abdominal pain, nausea, repeated vomiting, or diarrhea.
Main Causes and Clinical Examples
The most common triggers of anaphylaxis encountered in everyday clinical practice include foods, medications, and Hymenoptera stings.
- Foods: Accidental consumption of even a very small amount of a food allergen, such as milk, egg, nuts, wheat, soy, fish, or shellfish, may trigger a reaction in sensitized individuals.
- Medications and anesthesia: Administration of medications such as antibiotics, analgesics and antipyretics, certain chemotherapeutic agents, or substances used during anesthesia, including neuromuscular blocking agents, may cause anaphylaxis in susceptible individuals.
- Hymenoptera stings: A bee or wasp sting in a sensitized individual may trigger a severe reaction within minutes.
The treatment of choice for anaphylaxis, regardless of the cause, is adrenaline (epinephrine) administered using an auto-injector.
What Is an Adrenaline Auto-Injector?
Commonly referred to as an “adrenaline injection,” an adrenaline auto-injector is a specially designed, pre-filled, pen-shaped device containing a predetermined dose of medication. It is designed so that anyone—including the patient or a family member—can use it quickly and easily in an emergency, delivering the medication intramuscularly into the thigh with a simple action.
Which Patients Should Carry an Adrenaline Auto-Injector?
Absolute Indications
- Previous episode of anaphylaxis caused by food, latex, or airborne allergens.
- Poorly controlled asthma with coexisting food allergy.
- Bee or wasp venom allergy in patients who have not yet started venom immunotherapy.
- Food-dependent exercise-induced anaphylaxis (FDEIA): a specific form of anaphylaxis that occurs when consumption of a particular food is combined with physical exercise, usually within a few hours of each other.
- Idiopathic anaphylaxis: when the exact cause of anaphylaxis remains unknown despite a comprehensive medical evaluation.
- During and after completion of Hymenoptera venom immunotherapy in patients with additional risk factors or a history of a very severe initial reaction.
- Underlying systemic mastocytosis.
Relative Indications & Risk Factors
- Adolescents or young adults with food allergy and a history of mild to moderate allergic reactions.
- Previous mild or moderate reactions to trace amounts of food or to foods associated with a higher risk of anaphylaxis, such as peanuts, cow’s milk, fish, or shellfish.
- Patients with a history of mild or moderate reactions to foods, insect venom, latex, or airborne allergens who live a considerable distance from medical facilities or travel to remote locations for extended periods.
- Patients undergoing oral immunotherapy (OIT) for food allergy.
- Patients with a history of a severe reaction to Hymenoptera venom or medications and coexisting cardiovascular disease.
The Importance of Adrenaline in Anaphylaxis Management
- Rapid action: Adrenaline is the first-line treatment for anaphylaxis and can rapidly reverse critical symptoms such as low blood pressure, laryngeal swelling, and severe breathing difficulties.
- Prevention of deterioration: Prompt administration at the onset of anaphylaxis helps prevent the reaction from progressing to a potentially life-threatening stage.
The Importance of a Written Action Plan
Patients who have an indication for an adrenaline auto-injector should also receive a written Anaphylaxis Action Plan to ensure that it is used correctly. This is essential for the effective management of possible future reactions for the following reasons:
- Clear guidance: Every patient at risk of anaphylaxis should have an individualized, written action plan prepared under the guidance of an allergist.
- Reducing panic: The written plan provides step-by-step instructions on how to recognize symptoms, exactly when to use the adrenaline auto-injector, and what actions should be taken next.
- Safety wherever the patient may be: It serves as a practical guide not only for the patient but also for family members, school staff, and colleagues, helping ensure that everyone knows how to respond appropriately in a critical situation.
If you or someone close to you has a history of allergic reactions, a specialized allergy assessment can help establish an accurate diagnosis, guide the selection of appropriate treatment, and provide an individualized plan for preventing future episodes and managing them effectively should they occur.
