What Is Anaphylaxis? Symptoms and Treatment

What Is Anaphylaxis? Symptoms and Treatment

Anaphylaxis is a severe allergic reaction that usually begins suddenly within minutes after a person who is allergic to a substance comes into contact with that substance. During this reaction, whether or not the skin is affected, life-threatening systems such as the respiratory or cardiovascular system may be involved, leading to severe and potentially life-threatening symptoms such as shortness of breath, difficulty swallowing, fainting, and loss of consciousness.

During anaphylaxis, more than one organ system may be affected; however, vital systems such as the respiratory system or cardiovascular system may also be affected on their own. The important point is that the individual has been exposed to a medication, food, bee venom, or an allergen that can be inhaled. In the treatment of anaphylaxis, adrenaline should be administered immediately by intramuscular injection.

What Substances Can Cause Anaphylaxis?

In susceptible individuals, foods, orally taken medications in tablet or capsule form, intravenous fluids, injections, other medications administered intravenously, bee venom, and more rarely inhaled allergens such as horse hair and cat or dog dander can cause anaphylaxis.

In some very rare and specific cases, exposure to cold water or cold air may cause anaphylaxis in susceptible individuals. Exercise performed within a few hours after consuming a food or medication that would not normally cause an allergic reaction may also trigger anaphylaxis. In some cases and with certain triggers, previous sensitization is not required for anaphylaxis to occur. Anaphylaxis may also occur after the first exposure to that allergen.

What Is Anaphylaxis (Severe Allergic Reaction)?

Anaphylaxis is the most severe form of allergy. It usually occurs when a person with a known or unknown allergy comes into contact with the triggering substance and suddenly begins to develop allergic symptoms, often within minutes. Exposure to the substance may occur through ingestion, inhalation, intravenous administration, or intramuscular injection. The signs and symptoms that occur during anaphylaxis are severe and may be life-threatening.

Anaphylaxis is a severe allergic reaction. During anaphylaxis, more than one organ system, such as the skin and gastrointestinal system, may be affected. However, if vital systems such as the respiratory or cardiovascular system are affected on their own following exposure to an allergen, anaphylaxis should also be considered.

What Are the Symptoms of Anaphylaxis?

There may be skin redness, raised areas on the skin, itching on the palms and soles, or sudden widespread itching, but these are not always present. Whether or not there is skin involvement, life-threatening systems such as the respiratory or cardiovascular system may be affected.

Symptoms involving these systems may include a deep or barking cough, wheezing, shortness of breath, hoarseness, a change in the tone of the voice, difficulty swallowing, low blood pressure, palpitations, fainting, and loss of consciousness. The gastrointestinal system may also be affected, and severe cramping abdominal pain or repeated vomiting may occur. Loss of consciousness or feeling as though one is about to faint may indicate anaphylactic shock.

Symptoms of anaphylaxis include:

1. Sudden skin reactions: Rapidly developing redness, itching, urticaria (hives),and sometimes widespread rashes may occur. These are often among the first symptoms.
2. Swelling of the face and throat: Swelling may develop in the lips, tongue, eyelids, and throat. This may become life-threatening, particularly when the airways are affected.
3. Difficulty breathing: Wheezing, coughing, and chest tightness may develop because of narrowing of the bronchi. This may progress to respiratory failure.
4. Rapid and irregular heartbeat: The heart rate may increase as the body attempts to maintain circulation. Palpitations, dizziness, and weakness may occur.
5. Sudden drop in blood pressure: In severe cases, blood pressure may fall rapidly, which can cause fainting or loss of consciousness.
6. Gastrointestinal symptoms: Abdominal pain, nausea, vomiting, or diarrhea may occur.
7. Intense fear and anxiety: The person may experience a sudden fear of death, which may trigger anxiety and worsen the symptoms.
8. Cool and clammy skin: As circulation deteriorates, the skin may become cold, sweating may increase, and the person may appear pale.

Who Is at Risk of Anaphylaxis?

People with a known allergy and those who have previously experienced severe allergic symptoms after exposure to that allergen are at risk of anaphylaxis.

In addition, among people with allergies, infants, elderly individuals, adolescents, patients with uncontrolled asthma who have persistent symptoms, people who live far from healthcare facilities, and individuals with systemic mastocytosis are at increased risk.

Systemic mastocytosis is a condition in which excessive numbers of mast cells are present in organs such as the bone marrow, spleen, liver, and bones, with or without skin involvement.

Among individuals with food allergies, those with nut allergies are at risk of anaphylaxis and anaphylactic shock.

What Causes Anaphylaxis (Severe Allergic Reaction)?

Anaphylaxis occurs in individuals with a high degree of allergic sensitivity or severe allergies. Even if a person with an allergy has never experienced anaphylaxis before, it may develop after exposure to a large amount of the allergen.

It may also occur when the allergen rapidly enters the bloodstream, as can happen with medications or bee stings.

Individuals with systemic mastocytosis are also more prone to anaphylaxis. In systemic mastocytosis, excessive numbers of mast cells are found in organs such as the bone marrow, spleen, liver, and bones, with or without skin involvement. Because the number of mast cells is increased, stimulation of these cells can cause a larger amount of mediators to be released suddenly, resulting in severe allergic symptoms.

How Is Anaphylaxis Diagnosed?

Anaphylaxis is diagnosed according to the symptoms, signs, and clinical findings that occur in the individual.

During anaphylaxis, life-threatening systems such as the respiratory or cardiovascular system may be affected, whether or not there is skin involvement. Symptoms and findings may include shortness of breath, difficulty swallowing, repeated coughing attacks, wheezing from the lungs, a feeling of airway obstruction, palpitations, and a drop in blood pressure.

If anaphylaxis progresses, very severe and life-threatening conditions such as fainting and loss of consciousness may occur.

It should be determined whether the person experiencing anaphylaxis had been exposed before the event to a substance already known to cause an allergic reaction. If such exposure is present, anaphylaxis can be diagnosed more easily. Sometimes, however, the person may not be able to say or may not know whether they were exposed to an allergen.

In such patients, the serum tryptase level measured from a blood sample taken within the first 1–3 hours after the event may also provide useful information. If the level is above a certain value, it may support the diagnosis of anaphylaxis.

In these patients, the substance causing the allergic reaction should be identified, and the possibility of an underlying condition called mastocytosis should also be investigated.

Emergency Treatment for Anaphylaxis

In anaphylaxis, the patient should be positioned appropriately and an adrenaline injection should be administered immediately into the muscle on the outer side of the thigh.

If the patient has an adrenaline auto-injector and is not in a healthcare facility, the injection should be administered through the clothing into the upper outer part of the thigh while the patient is lying down.

Emergency medical services should be called, and the patient should be transported to a healthcare facility.

The patient should be positioned in a way that keeps the airway open. If the patient is in an ambulance or healthcare facility, oxygen should be given immediately by mask, monitoring should be started to follow the pulse and blood pressure, and intravenous access should be established for fluid administration.

If the patient has low blood pressure, intravenous fluid therapy should be given to increase the blood pressure.

If there is shortness of breath and breathing difficulty originating from the lungs, nebulized salbutamol may be administered by mask.

Antihistamines and corticosteroids may also be given. If there is shortness of breath due to swelling of the larynx, inhaled steroids may be administered by mask.

If there is not an adequate response after adrenaline administration and the clinical response has been assessed by a physician, adrenaline may be repeated at appropriate intervals.

Treatment of Anaphylaxis

In the hospital or emergency department, the first medication to be administered in anaphylaxis is adrenaline.

In children, the adrenaline dose should be calculated according to body weight. In adults, the maximum dose administered in a single injection is 0.5 mg.

If blood pressure is low, intravenous fluid support is essential.

The patient should be positioned in a way that keeps the airway open. If the patient is in an ambulance or healthcare facility, oxygen should be administered immediately by mask.

If the patient is in an ambulance or healthcare facility, monitoring should be started immediately, and intravenous access should be established for fluid administration.

If the patient has low blood pressure, intravenous fluids should be given to raise the blood pressure.

If there is shortness of breath and difficulty breathing originating from the lungs, nebulized salbutamol may be administered by mask. Antihistamines and corticosteroids may also be given.

If shortness of breath is caused by swelling of the larynx, inhaled steroids may be administered by mask.

If there is not an adequate response after adrenaline administration and the clinical response has been assessed by a physician, adrenaline may need to be repeated at appropriate intervals.

How Is First Aid Given to Someone Experiencing Anaphylaxis?

In anaphylaxis, the patient should be positioned appropriately.

The patient should be laid down on the floor, the head should be turned slightly to the left in a way that helps keep the airway open, and breathing should be checked.

If the patient has a previously known allergy and has an adrenaline auto-injector available, the medication should be administered through the clothing into the upper outer part of the thigh while the patient is lying down.

While the patient is lying down, slightly elevating the legs may increase blood flow to the heart and brain.

Emergency medical services should be called, and the patient should be transported to a healthcare facility.

How Can Anaphylaxis Be Prevented?

Anaphylaxis can be prevented by taking appropriate precautions to avoid the triggers that cause the allergic reaction.

It may be useful to carry a medical alert bracelet, necklace, or identification card indicating the allergy.

For example, a person with a drug allergy should always tell the doctor which medication they are allergic to during a medical examination or when a prescription is being written and should show their allergy card if they have one.

Before receiving medication by injection or intravenous infusion, the person should also inform the nurse about the allergy.

A person with a bee allergy should stay away from environments where bees are likely to be present, avoid areas with beehives, wear long-sleeved clothing and trousers outdoors, and avoid consuming uncovered food or drinks from open cans outdoors.

Perfumes with floral scents should not be used outdoors because they may attract bees.

Outdoors, clothing in dull or neutral colors should be preferred instead of bright and vivid colors, and multicolored or floral-patterned clothing should be avoided.

To prevent food-related anaphylaxis, foods that cause the allergy and foods containing those allergens should not be consumed.

When eating at a restaurant, foods prepared using utensils or equipment that may have come into contact with the allergenic food should be avoided.

Foods purchased outside should not be consumed if their ingredients are unknown.

When buying packaged foods from a market, labels should be read carefully, and packages containing the allergenic food should not be purchased.

Sometimes even trace amounts of an allergen can cause symptoms, so these types of packaged foods should also be avoided when necessary.

If the patient with a food allergy is an infant, everyone who may care for the baby, such as grandparents, aunts, or other caregivers, should be informed about the allergy and should not give the baby foods containing the allergen.

When children with food allergies start daycare or school, the school administration and teachers should always be informed.

Frequently Asked Questions About Anaphylaxis

Can anaphylaxis be fatal?

Anaphylaxis is a group of signs and symptoms that has the potential to be fatal.

If swelling of the larynx occurs within minutes after exposure to an allergen and causes shortness of breath, or if the cardiovascular system is affected and severe low blood pressure develops, these are among the most severe symptoms and can be life-threatening.

Immediate treatment with adrenaline is required.

What happens if I use the epinephrine injection incorrectly?

Epinephrine, also known as adrenaline, is administered with an adrenaline auto-injector when anaphylaxis develops after exposure to an allergen.

Incorrect administration may occur if the medication is not injected into the muscle, if the appropriate dose is not used, or if it is given when there is only skin involvement following allergen exposure.

After adrenaline is administered, side effects such as palpitations, rapid heartbeat, high blood pressure, dizziness, and trembling of the hands may occur.

These are expected side effects and are generally short-lived, lasting for several minutes.

If an auto-injector is used before full anaphylaxis develops, these types of side effects may occur, and the person should seek medical attention at the nearest healthcare facility.

During anaphylaxis, if the adrenaline dose is too low or the needle does not fully reach the muscle, the symptoms of anaphylaxis may continue.

If the diagnosis of anaphylaxis is certain and the first auto-injector dose was not administered properly or was ineffective, a second auto-injector may be required, and the patient should still be transported to the nearest healthcare facility.

A patient who has experienced anaphylaxis and received one dose of an adrenaline auto-injector should be safely transferred to the nearest healthcare facility.

The patient should be monitored there for heart rate, respiratory status, and blood pressure, and should remain under observation for at least four hours; in severe allergic reactions, observation for several days may sometimes be necessary under appropriate conditions.

Can mild allergic reactions progress to anaphylaxis?

Yes. Mild allergic reactions can progress to anaphylaxis.

A reaction may begin with mild allergic symptoms such as itching, redness, and raised areas on the skin and, within minutes, progress to shortness of breath and coughing. Severe abdominal pain and vomiting may also develop, and the clinical picture may progress to anaphylaxis.

Severe itching of the palms may be one of the first signs of anaphylaxis.

Allergens taken orally, such as foods or medications, may cause symptoms later than medications administered intravenously or allergens introduced through bee stings.

A person who has previously experienced mild symptoms after exposure to a known allergen may develop more severe allergic symptoms, including anaphylaxis, if exposed to a larger amount of that allergen later.

Can anaphylaxis recur after it has happened once?

Yes.

If a baby, child, or adult who has previously experienced anaphylaxis is accidentally exposed to the same allergen again, anaphylaxis may recur.

For example, a person with a wasp allergy who previously experienced anaphylaxis may develop it again after another wasp sting.

A baby or child who developed anaphylaxis after drinking milk may experience another reaction after eating ice cream containing milk protein.

Similarly, a young person with a penicillin allergy may experience anaphylaxis again if the same medication is accidentally taken.

Sometimes, other triggers that cross-react with the known allergen may also cause symptoms.

For example, a person who previously experienced anaphylaxis after taking a painkiller such as ibuprofen may also develop an allergy to a painkiller containing naproxen and experience anaphylaxis after taking it.

How Do We Know If We Are Experiencing Anaphylaxis?

Anaphylaxis can be recognized when certain signs and symptoms suddenly develop after exposure to a known or unknown allergen, such as medications, a newly consumed food, or a bee sting.

Anaphylaxis usually develops within minutes after a person who is allergic to a substance comes into contact with that substance and begins to experience severe allergic reaction symptoms.

There may or may not be skin symptoms such as redness, raised areas, or itching.

At the same time, life-threatening systems such as the respiratory or cardiovascular system may become affected, resulting in severe symptoms such as coughing, shortness of breath, difficulty swallowing, palpitations, low blood pressure, fainting, and loss of consciousness.

During anaphylaxis, more than one system may be affected, but vital systems such as the respiratory or cardiovascular system may also be affected on their own.

Which Medication Is Used in Anaphylactic Shock?

In anaphylactic shock, adrenaline is the first medication to be administered.

In shock, airway patency and heart rate should immediately be checked, intravenous access should be established, and fluid replacement should be started.

It is important for these patients to be monitored under intensive care conditions.

If the patient does not improve after the first dose of adrenaline, adrenaline may be injected intramuscularly two more times at intervals of 5–15 minutes, with the clinical response checked after each dose.

If there is still no improvement, an intravenous adrenaline infusion should be started under intensive care conditions.

In anaphylactic shock, medications such as dopamine and dobutamine, which support heart rhythm and contraction, may be prepared and administered by intravenous infusion to help restore blood pressure.

The patient should be monitored very closely and should be managed in an intensive care setting.

Other medications used in allergy treatment should also be administered as appropriate.

Can Anaphylaxis Resolve on Its Own?

Some allergies may resolve spontaneously over the years, such as milk and egg allergies that begin in infancy.

It has also been observed that some penicillin allergies may disappear after about five years.

However, if a person has experienced a severe allergic condition such as anaphylaxis, the likelihood that the problem will simply resolve on its own is very low.

Immunotherapy may be used in selected patients who have experienced anaphylaxis due to certain allergens, such as bee venom, and in some specific allergy conditions.

With this type of treatment, the risk of anaphylaxis after future exposure to the allergen or the severity of the reaction may be reduced.

What Is the Mortality Rate of Anaphylaxis?

The mortality rate from anaphylaxis is approximately 0.5–1 per million people.

This rate is lower in children and higher in older adults.

In adults, accompanying cardiovascular and respiratory diseases and the use of additional medications may act as risk factors that reduce the response to adrenaline during anaphylaxis and prevent rapid improvement.