Anaphylaxis

About

Anaphylaxis is a severe and potentially life-threatening allergic reaction that can happen suddenly and without warning. It is caused by an allergic response to a foreign substance, usually a food, a medication, insect stings, or latex. Symptoms of anaphylaxis can vary, but typically include skin rash, hives, itchiness, swelling of the face and extremities, difficulty breathing, and a drop in the blood pressure. Prompt treatment is needed to prevent the reaction from worsening and, potentially, resulting in death. Treatment usually involves the use of epinephrine and, in some cases, antihistamines or corticosteroids.

Symptoms

The symptoms of anaphylaxis can vary from person to person, but generally include some combination of swelling, itching, hives, tightness in the throat or chest, wheezing and/or difficulty breathing, nausea and vomiting, abdominal cramps, diarrhea, dizziness, and a drop in blood pressure. In severe cases, anaphylaxis can cause loss of consciousness and even death.

Causes

The most common known causes of anaphylaxis are certain foods, such as peanuts and shellfish, medications like antibiotics, latex, and insect stings. Other potential causes can include exposure to certain chemicals or environmental factors, such as pollen or animal dander.

Risk factors

Risk factors for anaphylaxis include:

A history of allergies and previous anaphylaxis episodes
Having multiple allergies
Certain medications, such as antibiotics and nonsteroidal anti-inflammatory drugs
Foods, including peanuts, tree nuts, shellfish, cow’s milk, soy, and eggs
Insect stings, such as from bees and wasps
Exercise
Latex
Exposure to cold temperatures, such as cold water or cold air

Diagnosis

Anaphylaxis is typically diagnosed based on a combination of observation, physical examination, and medical history. During the physical examination, the doctor may look for signs of hives, swelling, difficulty breathing, and dizziness. The doctor may also ask about any recent exposure to allergens, such as food, latex, drugs, or insect stings. Medical tests, such as a blood test or skin prick test, may also be ordered to check for allergies. In some cases, an anaphylactic reaction may be mistaken for an asthma attack and vice versa.

Sub-types

The various subtypes of Anaphylaxis can be broadly classified into three main categories: immunoglobulin (IgE)-mediated Anaphylaxis, non-IgE-mediated Anaphylaxis, and mixed Anaphylaxis.

IgE-mediated Anaphylaxis is caused by an allergic reaction to an antigen, resulting in the release of immunoglobulin E (IgE). It is the most common cause of anaphylaxis and is typically triggered by food allergies, insect bites/stings, medications, or contact with certain environmental allergens. Symptoms typically occur within minutes to hours of exposure and can include skin hives and itching, swelling of the throat and tongue, low blood pressure, and respiratory distress.

Non-IgE-mediated Anaphylaxis is a less common form of anaphylaxis and is caused by an immune system response to an offensive allergen without the involvement of IgE. This type can be difficult to diagnose since symptoms often develop slowly over time, typically hours to days after exposure. Symptoms can include skin flushing, abdominal pain, nausea, and breathing difficulties.

Mixed Anaphylaxis is a combination of IgE-mediated and non-IgE-mediated anaphylaxis. Symptoms can vary and may include any of the above symptoms experienced with either type of anaphylaxis.

Treatments

Treatment for anaphylaxis is prompt and aggressive utilizing a combination of epinephrine, airway management, and supportive care.

Epinephrine: Epinephrine is the cornerstone of treatment for anaphylaxis and is given as an intramuscular injection in the anterolateral thigh.
Airway Management: Rapid airway management may be necessary in cases of laryngeal edema or respiratory distress.
Corticosteroids: Corticosteroids are given intravenously to reduce the potential for late phase reaction and help reduce inflammation.
Antihistamines: Antihistamines are given to reduce the symptoms of an allergic reaction, such as skin rash, hives, and itching.
Bronchodilators: Bronchodilators are given to treat bronchoconstriction and improve airway patency.
Fluid Resuscitation: Fluid resuscitation is used to treat hypotension caused by shock or anaphylactoid reactions.
Oxygen Therapy: Oxygen therapy is used to increase the amount of oxygen available to the body to treat hypoxia.

Prevention

There are a variety of steps that can be taken to reduce the risk of anaphylaxis:

Wear medical alert jewelry or carry an EpiPen.
Tell your doctor about any allergies or allergic reactions you have had in the past.
Know your triggers, as well as signs and symptoms of anaphylaxis, and avoid them whenever possible.
Avoid eating or coming in contact with any food you are allergic to.
When in doubt, ask a doctor or pharmacist if a medication contains an allergen.
If using latex gloves, use non-latex gloves or alternative protective equipment.
Take all medications as prescribed.
Exercise regularly to keep your immune system strong.
Visit an allergist for regular check-ups and to get an action plan for any symptom of anaphylaxis.
0. Ensure all family members and caregivers understand the signs and symptoms of anaphylaxis.

Gender differences?

There are no suggested gender-specific differences in the presentation or management of anaphylaxis. According to the European Academy of Allergy and Clinical Immunology, any differences in risk, presentation, diagnosis and clinical effects of anaphylaxis are likely due to the underlying conditions and not gender. Both men and women may experience the same signs and symptoms, including hives, difficulty breathing, and a feeling of tightness in the throat. Furthermore, the same treatments are used regardless of gender, such as the administration of epinephrine, antihistamines, or corticosteroids. There is, however, gender-specific research that suggests males have higher mortality rates with regards to anaphylaxis, but this could be attributed to the fact that males are more likely to have underlying health conditions that may increase the prognostic risk.

Nutrition

Nutrition plays an important role in the management of Anaphylaxis. Eating a healthy, balanced diet of nutritious foods can help to improve overall health, which can reduce the risk of anaphylactic reactions. Additionally, avoiding allergenic foods can help to reduce the risk of severe reactions. Maintaining proper nutrition is also essential for helping to boost the immune system, which can also help to reduce the risk of anaphylaxis.

Physical Activity

Physical activity can increase the risk of anaphylaxis because it causes the body to produce more sweat and can cause more irritants and allergens to enter the body, thus triggering an allergic response. In addition, physical activity increases the heart rate, which can cause an increase in blood pressure, leading to constriction of the airways and anaphylaxis. As such, it is important for individuals who are at risk of anaphylaxis to take preventative measures to reduce the risk, such as avoiding triggering allergens, taking medication for allergies, and wearing protective clothing to limit skin exposure.