Exercise-Induced Anaphylaxis - A Rare but Potentially Fatal Condition

What Is Anaphylaxis?

Anaphylaxis is a severe and fatal allergic reaction that shows its symptoms within seconds to minutes. It is the state of shock that is caused by a flood of chemicals that the body releases as a response to allergies. The body’s immune system can be triggered by various attributes such as food, medications, exercise, insect venom, and a particular material (latex). Within a moment of exposure to allergens, the body shows symptoms such as hives, low blood pressure, swollen throat, dizziness, nausea, and skin reactions. For instant treatment, epinephrine pens or other oral medications are prescribed to children who are more sensitive to allergens.

What Is Exercise-Induced Anaphylaxis?

Among many types of anaphylaxis, exercised-induced anaphylaxis is a very rare but fatal reaction. Exercise-induced anaphylaxis (EIA) is a hypersensitivity reaction caused by extensive exercise. Many physical activities trigger this kind of reaction in the body. Usually, moderate to severe intensity exercise can induce this reaction. If the physical activity continues, there are severe symptoms seen in the patients, such as angioedema, laryngeal edema, hypotension, and at last cardiovascular failure.

It is a condition that occurs due to an overdrive of the immune system induced by an allergen and causes the release of certain mediators such as histamine and tryptase. These chemicals are produced by mast cells in the body, and they are the reason behind all allergic reactions.

What Are the Triggers for Exercise-Induced Anaphylaxis?

There are many triggers that cause this reaction in the body. Sometimes in spite of the contact with allergens, a person can not feel any symptoms. However, if they exercise or do extensive physical activity right after this contact with allergens, it can trigger anaphylaxis in the body. An allergist will take a closer look at these to determine the primary cause behind the reaction. Some common food triggers for exercise-induced anaphylaxis include

• Alcohol.

• Apples.

• Beef.

• Eggs.

• Fish.

• Milk.

• Legumes.

• Mushrooms.

• Nuts.

• Pork.

• Soy.

• Shellfish.

• Peaches.

• Tomatoes.

• Wheat or wheat protein.

What Are the Causes of Exercise-Induced Anaphylaxis?

The pathophysiology behind this disorder is not clearly understood. However, research suggests that the cause of the symptoms are production and release of chemical mediators like histamine and tryptase. These chemicals are the products of the activation and degranulation of mast cells (the type of white blood cells found in the connective tissue) in the body. If the patient is suffering from exercise-induced anaphylaxis, there is a significant decrease in the threshold of mast cell degranulation seen. Although there is no evidence of the actual reason behind this.

The symptoms of this reaction are caused by moderate exercises, such as jogging, dancing, cricket, and tennis. There is no particular physical activity that causes the same chain of reaction even after the severe form of the activity.

What Are the Signs and Symptoms of Exercise-Induced Anaphylaxis?

There are multiple signs and symptoms associated with exercise-induced anaphylaxis, such as:

1. Skin:

• Urticaria or skin rashes caused by food, medicines, or other irritants.

• Angioedema or swelling underneath the skin caused by allergens.

• Redness.

• Rashes.

• Pruritus causes an uncomfortable and irritating sensation that further leads to an extreme urge to itch the skin. This can involve any part of the body.

• Flushing is a very common condition. However, in conditions such as fever or anaphylaxis, the body part with the maximum blood flow shows sudden redness. It is due to increased blood flow and enlargement of the blood vessels.

2. Brain:

• Anxiety.

• Headache.

• Confusion.

3. Stomach:

• Nausea.

• Diarrhea.

4. Airway:

• Respiratory distress due to allergic reactions, there are symptoms such as difficulty in breathing. It is caused by airway obstruction or swelling due to anaphylaxis.

5. Heart:

• Hypotension or a sudden drop in blood pressure. It is one of the classic symptoms of anaphylaxis.

• Cardiovascular failure is an extreme condition of anaphylaxis. These symptoms need immediate medical attention.

How to Diagnose Exercise-Induced Anaphylaxis?

Diagnosis of exercise-induced anaphylaxis is based on the age and severity of the condition, such as:

• Physical Examination: Patients with exercise-induced anaphylaxis have symptoms such as hives, angioedema, or cardiovascular collapse. Each complication related to this disorder is associated with the classic set of symptoms. With physical examination, doctors can check for these signs and diagnose the condition.

• Case History: Right after a physical examination of the rashes or other symptoms, doctors ask detailed questions about the child’s routine. Parents are also asked if a child had any particular food or particular medicine before the reaction. Additionally, the details about past medical history or medical issues are also asked to evaluate the condition. All of this information together can help in further diagnosis.

• Clinical Examination: During this, the patient’s other clinical signs are checked, such as edema, fever, burns, or flushed skin of any of the body parts. All the symptoms are carefully diagnosed along with clinical history to distinguish the episodes of exercise-induced anaphylaxis.

How to Manage Exercise-Induced Anaphylaxis?

This condition must be treated immediately as a medical emergency, especially in children. Management and treatment of exercise-induced anaphylaxis are the same as any other anaphylaxis. Every reaction must be treated as per the severity and type of hypersensitivity in patients. Treatments for hypersensitivity reactions are:

• Adrenaline (intramuscularly, decreases airway swelling and cardiovascular symptoms).

• Systemic glucocorticosteroids (decrease inflammatory reactions).

• Antihistamines (to counteract the effect of the release of histamine).

• If the anaphylaxis is caused by a particular food, that food item should be avoided for at least four to six hours prior to the exercise.

• If the food is causing extreme allergic reactions in an individual, it is better to avoid it.

• If the medication is causing any allergies in children, parents should immediately seek a doctor’s consultation for a change of prescription.

• If a child is doing extensive physical activities, doctors should teach parents to recognize the very first sign of anaphylaxis.

• In the case of hypotension, parents should learn the importance and steps of Trendelenburg's position to expedite the perfusion of vital organs.

• Auto-injectable Adrenaline or Epinephrine should be handy, especially if the child is involved in extensive physical activity or is allergic to any food.

Conclusion

Exercise-induced anaphylaxis is a rare but potentially fatal condition. The causes behind this disorder are known but still not completely understood. It is very important for parents and doctors to diagnose this condition at an early stage, as some of the symptoms can cause a life-threatening situation in children. Moreover, parents should also keep some of the basic medication handy with the doctor’s recommendation for immediate care.