Anaphylactic shock: Anaphylaxis as an exaggerated, severe allergic reaction?

An anaphylactic reaction is a severe form of allergic reaction. Also abbreviated as anaphylaxis. Anaphylactic shock is the most severe stage of anaphylaxis. It endangers a person's life immediately.

Important terms for allergy and anaphylaxis

An allergic reaction is an exaggerated or inappropriate response of an organism, and therefore its immune system,  to an allergen. An allergen can be a common substance found in the environment that is not normally harmful to humans.

An allergen, also known as a type of antigen, elicits an excessive immune response in an allergy sufferer, resulting in an allergic reaction. We also know of atopic allergies, the cause of which is a genetic predisposition to the production of IgE antibodies.

Anaphylaxis is a more severe degree of allergy. It affects several body systems and organs. It occurs at a higher intensity than allergies. It endangers human health and life. We also know the term anaphylactoid reaction, although it is similar to anaphylaxis, it is not caused by an immune response.

Anaphylactic shock is the most severe form of anaphylaxis, directly endangering the life of the victim. Shock is a sudden change in micro and macrocirculation. It leads to a disorder of the blood supply to the tissues, and thus to reduced oxygenation and a disorder of cellular metabolism.

If anaphylactic shock is not treated, failure and organ damage leading to death. Among ordinary people, the name shock is used as a psychological reaction, for example to acute stress. However, this naming is incorrect.

The term shock refers to an acute, life-threatening condition for a blood disorder. It affects several body systems and organs. For example, the cardiovascular system, lungs, kidneys, adrenal glands, brain, liver. It has three phases, a compensation phase, a decompensation phase, and an irreversible phase.

While  in the first compensatory phase , the body tries to maintain the blood supply to the necessary organs, thus the brain, heart, kidneys. In the decompensation phase, the changes deepen, the blood pressure decreases, and the blood supply to the tissues and organs deteriorates.

If the shock is not treated by this point, an irreversible phase occurs. The most serious phase is thus irreversible phase while having irreversible change and leading to permanent organ damage or even death.

The shock is categorized  into:

• hypovolemic when there is not enough blood in the blood vessels as a result of bleeding or dehydration
• cardiogenic when the heart function as a pump fails
• obstructive, caused for example by pulmonary embolism
• distributional  occurs when blood vessels dilate excessively, such as in anaphylaxis or sepsis (blood poisoning)

Read also:  Article with general information about shock .

What is anaphylaxis?

These terms are important to distinguish between allergy, anaphylaxis, and anaphylactic shock. As the origin of the difficulties may be the same, however, the difference stands in the intensity of the course. Allergy is therefore a poison in the field of health problems, which should not be underestimated at any cost.

The word allergy is formed from two Greek words, namely allos, meaning a changed state, and from the word ergon, meaning work, reaction. It was created by physicians Clemens von Pirquet and Béla Schick in 1906.

Anaphylaxis is a generalized allergic reaction, an allergy that has spread to the whole body. It affects several body systems.

It affects, for example, organ systems such as:

• circulatory
• breathing
• nervous
• skin
• digestive 

Anaphylactic shock is a life-threatening condition based on severe anaphylaxis. It is manifested by a  decrease in blood pressure, circulatory insufficiency, and unconsciousness.

The body is immunized on the first encounter with the allergen, which makes antibodies.

It does not show a typical allergy. Subsequently, in the second antigen challenge, an exaggerated immune response occurs.

In this case, IgE antibodies identify the given antigen, which triggers the allergic cascade. In addition to the IgE form, other mechanisms are known. However, the IgE type of reaction is the most common, up to 60 percent. Subsequently, other mediators are involved in allergy.

In the case of an allergic or anaphylactic reaction, there are released substances such as:

• histamine
• serotonin
• tryptase
• heparin
• adenosine
• prostaglandin D2
• interleukins
• leukotrienes

In some cases, anaphylaxis takes place in two phases.

This is a few seconds to minutes after the encounter with the antigen, namely allergen. The second phase of the anaphylactic reaction can

Allergy or anaphylaxis as such is caused by an excessive response to the antigen. An antigen, an allergen, is a substance that is not normally dangerous to the body. However, the body marks it as unwanted on the first contact.

Subsequently, in the second contact with it, reacts inappropriately. This can be caused by allergens that are normally found in the environment. Anaphylactic shock is the most severe form of reaction to an allergen entering the body.

The table lists some of the substances that often cause allergies

Allergy to the food component,  gluten and lactose .

An allergic reaction has its typical manifestations. These can be local or general. During anaphylaxis, several body systems and organs are affected. Such as the skin, cardiovascular system, or respiration.

Manifestations of anaphylaxis depend on several factors, such as:

• type of allergen
• place and method of penetration into the body, ie through the digestive tract, skin, injection
• degree of sensitivity, sensitization of the organism
• target organ or tissue

The table shows the symptoms of anaphylaxis with respect to the body system

The most important is the anamnesis of the affected person and the clinical manifestations of allergy, including anaphylaxis. It is very important to recognize the allergen. This will often help to prevent or treat the allergy that has arisen.

The type of allergen can be determined if the substance after which the reaction has occurred is known. Another method is laboratory tests and a skin allergy test. IgE, an increase in histamine in the blood or urine is determined. Mucus and nasal secretions can also be examined to determine the presence of eosinophils.

The diagnosis of anaphylaxis under the action of a known allergen is simple. In the case of the initial reaction, it is all the more difficult because the allergen is not yet known. But if you experience symptoms typical of an allergy, such as after being bitten by a bee, the diagnosis is clear.

Within difficulties, it is important to rule out another cause (hereditary angioedema, arrhythmia, etc. according to symptoms). Especially if the cause of the problems is not known. Differential diagnosis is important for the detection of other serious diseases.

The allergic reaction in the first phase takes place in seconds to minutes.

The second phase (20% of cases) may occur after 6 - 24 hours.

The first is mostly skin manifestations. And the redness,  itching, hives, or a rash. Angioedema, a swelling of the soft parts of the skin, also occurs frequently. Typically it is the area of ​​the hands, face, but also neck.

As mentioned, the course depends on several factors and is individual. More serious problems occur after intravenous administration of drugs, but also after being bitten by a bee in an area close to the heart and face.

After the allergen enters the body, a cascade of immune reactions is triggered. Vasoactive substances (acting on the blood vessels), such as histamine, prostaglandin D2, leukotrienes, and also substances that affect airway contraction, are flushed into the blood.

The effects of these substances are manifested in particular as:

• airway contraction, ie bronchoconstriction
• vasodilation
• increased permeability of capillaries, small vessels for fluids (angioedema)
• increased secretion of mucus mucous membranes of the respiratory tract, both lower and upper
• platelet aggregation and activation resulting in DIC (disseminated intravascular coagulopathy)

As a result, there is a transfer of body fluids into the intercellular space, and thus the loss of fluids from the bloodstream, but also vasodilation. This will lower the blood pressure and speed up the heart rate.

Narrowing of the airways results in difficulty breathing  (dyspnoea), and wheezing may be heard, as in an asthma attack. Respiration is also exacerbated by increased mucus production in the lower respiratory tract and is associated with hoarseness when breathing.

In addition to the above swelling of the soft tissues, edema of the larynx and the laryngeal flap is very severe. Which can result in obstruction, that is airway obstruction,  then choking to breathing shortage.

The result is respiratory failure and, if early treatment or resuscitation care is not initiated, death. Equally dangerous is a failure of heart function, due to a malignant arrhythmia or ischemia, that is, a lack of blood supply to the heart muscle, and thus a heart attack.

In shock, some symptoms result from worsened blood flow to the brain. These include altered consciousness (apathy, aggression), collapse, body cramps, and unconsciousness. Besides, in shock, it is possible to observe pale to marble discoloration of the skin, cold sweat.

The digestive system responds with general exertion, vomiting, abdominal pain. Sparse stools may also be associated. Urine production decreases to a halt and renal colic may occur. Withdrawal of the bladder can cause urine to leak. Uterine contraction is particularly risky during pregnancy.

Although the allergic reaction is mild for the first time, a professional examination is very important. The second reaction may be intense. However, although the course of anaphylaxis can have a fatal end, fortunately, there is an effective and rapid treatment that prevents the development of anaphylactic shock into its irreversible form.