Type II Allergy

By | June 10, 2022

The classification of allergy types, such as type II allergy, according to Coombs and Gell dates back to 1963 and is actually outdated according to the current state of immunological research.

What is Type II Allergy?

For didactic reasons, however, it is still popular and is an integral part of medical training. In any case, it is still helpful today for understanding the causes of allergies. For what does the abbreviation cms stand for, please visit usvsukenglish.com.

According to this classification, type II allergy is a reaction of the so-called “cytotoxic type”, in which antibodies circulating in the blood recognize cell-bound antigens and lead to an often biologically unnecessary or excessive defense reaction of the organism. A classic example of this is blood group incompatibility in blood transfusions.


The causes of a type II allergy require a deep insight into biochemistry and immunology and are not always understood down to the last detail, even given the current state of research.

Basically, however, the antigen-antibody reaction is a useful part of our immune system : This knows the surface structure of its own body cells down to the last detail and is at the same time on the lookout for everything that it does not recognize as “self”. The antibodies circulating in the blood are of important importance for this, as they are directed against many known structures of bacteria or viruses, for example, to which they bind and which they can then clump together with other immune cells and kill.

The same also works with blood groups: There are over 200 different blood group systems in the body, but the most important in medicine are the AB0 (pronounced AB-zero) system and the so-called Rhesus factor. If, as a patient with blood group A, you accidentally receive a blood donation with blood group B in the hospital, the antibodies circulating in your own body against the blood group antigen B, which is on every transfused red blood cell, ensure that the blood clots and is life-threatening Defense reaction of the own body against the “foreign body” B begins.

This would be a classic example of a Type II reaction and, incidentally, a serious medical error that would cost the treating physician his license to practice medicine.

Symptoms, Ailments & Signs

The first symptoms of type II allergy appear after six to twelve hours. They don’t turn out uniformly. The intolerance results from the blood group and medication. Above all, the body’s own blood and the thyroid gland are affected.

The cytotoxic type is also referred to as blood group incompatibility. A lack of blood platelets brings with it a tendency to bleed. Patients complain of frequent nosebleeds. Bruises form on different parts of the body. So-called petechiae, i.e. punctiform skin hemorrhages, also come to light. In extreme cases, bleeding in the brain and in the gastrointestinal tract is possible.

In other cases, the antibodies work against the thyroid. An overactive thyroid leads to uncontrollable sweating and nervousness. Those affected can sleep poorly at night. They also regularly complain of diarrhea. Constant hoarseness accompanies everyday life. In addition, other side effects sometimes occur that do not appear to be directly related to the type II allergy.

Those affected can no longer perform mental work. Your ability to concentrate is impaired. The performance when coping with everyday work also decreases. If the type II allergy is not treated in the long term, ulcers can develop. The thyroid gland is particularly affected. Some of those affected often remain listless and suffer from increased sensitivity to cold.

Diagnosis & History

In addition, there are other completely different examples of type II allergies : In the case of immunohemolytic anemia, the red blood cells are also destroyed – however, this is an autoimmune disease in which the body forms antibodies against its own blood cells for an ultimately unclear cause.

For example, so-called cold antibodies always bind to the blood cells and trigger their destruction when they come into cold regions of the body. People with such an immune hemolytic anemia therefore often have severe pain in their hands and feet.

Another variant of a type II reaction is the so-called Goodpasture syndrome, a very rare but severe autoimmune disease in which, among other things, blood vessel cell walls in the kidneys are attacked and destroyed by the body’s own antibodies. This leads to blood in the urine, dropsy ( oedema ) and a sometimes very rapidly progressive destruction of the kidney function up to the point where dialysis is required.

Incidentally, the reaction between antigen and antibody does not always lead to the destruction of the target cells: In one of the most common thyroid diseases, Graves’ disease, there is also a type II reaction in which the target antigen is activated by the antibody and leads to a leads to overactive thyroid. Heart palpitations, feeling hot, hair loss and weight loss despite cravings are possible expressions of this hyperfunction.


Type II allergies are much rarer than type I allergies. However, it often develops serious complications that can sometimes be fatal. As already mentioned, the triggers are often drugs or blood transfusions. After contact with the allergen, the body’s own cells in the blood-forming system, such as erythrocytes, thrombocytes and granulocytes, are destroyed a few hours later.

This type of allergy therefore often leads to hemolytic anemia, transfusion incidents, thrombocytopenia or agranulocytosis. Each of these diseases carries the risk of a life-threatening complication. In hemolytic anemia, the red blood cells are destroyed. The result is anemia, which in very severe cases can even make a blood transfusion necessary.

The blood breakdown products cause jaundice. The disease is characterized by increasing tiredness and a reduction in physical and mental performance. In addition to the administration of certain medications and antibiotics, hemolytic anemia can also occur with a blood transfusion. Then there is talk of a transfusion incident. In some cases, hemolytic anemia is fatal.

In thrombocytopenia, the thrombocytes (platelets) responsible for blood clotting are destroyed. As blood coagulation is disturbed, bleeding can occur constantly, which in severe cases can also lead to life-threatening blood loss. Agranulocytosis, in turn, manifests itself through the destruction of white blood cells with fever, mucosal ulcers, skin necrosis, tonsillar angina, mouth sores or localized lymphomas.

When should you go to the doctor?

Type II allergies should usually always be treated and examined by a doctor. This disease cannot heal on its own, so the patient is always dependent on treatment by a doctor in order to prevent further complications or a further deterioration of the symptoms. The earlier the allergy is detected, the better the further course of the disease.

The doctor should be consulted if the person concerned suffers from nosebleeds or bruises on the skin after taking medication. Bleeding on the skin can also indicate a type II allergy and should be checked by a doctor. Some patients also suffer from diarrhea or concentration problems. Sleeping problems can also indicate a type II allergy. Especially after taking certain medications, these symptoms can occur and have a negative impact on the quality of life of those affected. In most cases, type II allergies can be easily identified by a general practitioner. Further treatment depends on the extent of the symptoms, so that no general prediction can be made.

Treatment & Therapy

There are many other examples of type II allergy reactions, some of which are very specific. The treatment options are correspondingly different. In many cases, the doctor’s only option is to suppress the immune system with cortisol preparations or other immunosuppressive drugs.

In the case of a faulty blood transfusion, which is the classic example of type II allergy, the only thing that helps is stopping the transfusion immediately, treating the circulatory shock symptomatically and monitoring the affected patient in intensive care.


Since type II allergies are all very complicated medical contexts, as an individual you can’t do anything general to prevent them. For medical staff, on the other hand, this is part of everyday life.

The prevention of transfusion reactions, for example, is one of the most closely monitored areas of medicine and involves multiple blood tests and multiple queries of patient data to ensure that the right blood is not given to the wrong person or vice versa.


Follow-up care for a type II allergy involves a number of measures that depend on the allergy type and the severity of the allergy. After the allergy has been diagnosed, a specialist doctor must first be consulted so that other diseases can be ruled out and hyposensitization or other treatment measures can be carried out. It is important to provide early information about the necessary diagnostic and treatment options.

Patients with a type II allergy should be treated promptly if possible. Once the type II allergy has been identified and treated, no further visits to the doctor are required unless complications arise. If the allergic symptoms increase or new symptoms appear, the responsible allergist must be informed.

Patients who suffer from an allergy should also visit their family doctor at regular intervals. This is particularly necessary if other allergy types or intolerances are present. Regular information about new therapy methods can improve the quality of life of patients in the long term.

You can do that yourself

Type II allergy can cause serious symptoms and complications. Prevention and rapid self-help in the event of an allergic reaction are all the more important.

If there are signs of toxic shock, an ambulance must be called first. The affected person must lie down quietly and, if possible, drink a lot. If available, rescue medication may be administered. In the best case, the patient wears an allergy card, which shows the type and treatment of the allergy. The arriving emergency doctor must be informed immediately about the symptoms so that the allergic reaction can be treated in a targeted manner. However, the most important measure in the event of an allergy is to avoid allergic reactions.

Type II allergies in particular, which can cause complications such as thrombosis and cardiovascular problems, must first and foremost be treated preventively. The allergy sufferer must avoid the triggering substances and, if necessary, adapt their diet and other lifestyle habits to the allergy. A nutritionist or allergist can name measures for self-help and support those affected in targeted prevention. The German Skin and Allergy Aid e. V. and the German Allergy and Asthma Association e. V. offer those affected further options and contact points.

Type II Allergy