Type III Allergy

By | June 10, 2022

Type III allergy is a so-called “immune complex type” reaction. Here, antigen-antibody complexes are deposited in the vessel walls of the blood vessels and cause local inflammation there, as a result of which the vessels narrow and become blocked and the affected organs can be destroyed.

What is type III allergy?

The division of allergy types (including type III allergy ) into four different categories is fairly “old hat” in medicine: The scientists Coombs and Gell published this classification in 1963 and since then it has been an integral part of medical studies and Training in medical nursing professions.¬†For what does the abbreviation hyperprolactinemia stand for, please visit usvsukenglish.com.

According to the current status of immunological research, the Coombs and Gell classification can actually be regarded as outdated today. Nevertheless, it is often used for didactic reasons and is suitable for understanding the pathophysiological processes behind the very diverse manifestations of allergic reactions.

Serum sickness or intolerance to certain medications such as penicillin belong in this category, as well as certain kidney and lung diseases or rheumatoid arthritis.


The antigen-antibody reaction is actually a very useful part of our everyday immune system and helps the body to recognize and mark invading bacteria and viruses on the mucous membranes or in the bloodstream and “throw them to the scavenger cells”.

In many autoimmune diseases, this reaction is directed against the wrong antigens: it is no longer recognizing bacteria, but components of the patient’s own blood or cell surfaces.

Soluble antigen-antibody complexes are then deposited in the vascular walls and in the tissue and trigger inflammatory reactions. These can get so bad that the affected organs are damaged.

Symptoms, Ailments & Signs

Signs of a type III allergy are noticeable within a few hours. Vascular inflammation usually occurs. Red hemorrhages in a round shape indicate the disease. Arteries and veins are usually affected. In addition to local signs, symptoms can also be felt all over the body.

In type III allergies, leukocytes release enzymes that damage the tissue. This can cause ulcers to appear and individual areas of skin to die off. Inflammation of the vessels is common, what experts refer to as the Arthus reaction. Sometimes the so-called serum sickness occurs with a time delay. The symptoms vary in intensity and are often mild.

So it stays with redness, itching and swelling. The symptoms go away on their own after a while. Inflammation of the kidneys or shock are the exception. Type III allergies often spread to the entire body. Then the pathogens have settled in the bloodstream.

Those affected regularly complain about problems in the cardiovascular system. The heartbeat accelerates without there being a stressful situation. Blood pressure plummets. Fever and diarrhea can accompany this condition. If there is renewed contact with the allergens, this can promote a long-lasting illness.

Diagnosis & History

In the case of the so-called serum sickness, this is a fundamentally sensible reaction. If you inject a person with certain proteins from the serum of other animal species, he normally does not tolerate them, they are recognized as foreign in the blood and marked by antibodies.

Sometimes, however, medicine requires antiserum or vaccine serum, which can only be produced in animal species. Although this is cleaned and chemically processed in the laboratory, some bodies still recognize it as foreign and fight against it. Then there is a type III allergy. Antisera are used, for example, as protection against snake venom or as a passive vaccine to prevent infection with the hepatitis B virus if you have already had contact with it.

Some people also have an allergic reaction to drugs such as penicillin, in the sense of a type III reaction. Symptoms of this reaction are skin rash, fever, joint inflammation, kidney failure with edema, diarrhea. The type III reaction is also known as the delayed-type reaction because the symptoms do not appear until six to twelve hours after exposure to the triggering antigen.

Other examples of type III allergies lead deep into the pathology of autoimmune diseases: Panarteritis nodosa leads to inflammation of vascular walls throughout the body with vascular occlusions or internal bleeding.

Characteristic autoantibodies can be detected here in the laboratory. In immune complex glomerulonephritis, which can also be triggered by harmless respiratory infections, antigen-antibody complexes are deposited in the tiny blood vessels of the kidneys and block them. Anyone who suddenly notices swelling in the face or legs two to four weeks after tonsillitis or a decrease in the amount of urine could be suffering from such an autoimmune phenomenon that fortunately can often be treated well and at short notice.

Rheumatoid arthritis, lupus erythematosus or exogenous allergic alveolitis, the latter also known as farmer’s lung, are type III reactions. In the case of farmer’s lungs, years of inhaling farm-specific dust, especially mold, leads to an antigen-antibody complex deposit in the lungs, which leads to inflammation and subsequently to shortness of breath and high blood pressure in the pulmonary circulation. Similarly, there is also, for example, a winegrower’s lung, a woodworker’s lung or a cheese washer’s lung.


Type III allergy, along with type II allergy, is one of the types of allergy with the highest risk of complications. During the active uptake of immune complexes from allergens and IgG and IgM antibodies by granulocytes, tissue-damaging enzymes are formed which can lead to serum sickness, allergic vasculitis or exogenous allergic alveolitis. Serum sickness results from the injection of antiserum or vaccine serum of animal origin.

This creates immune complexes that are deposited in the joints and small blood vessels and can cause inflammation there. The disease, which is associated with fever, rash, joint pain and swelling of the lymph nodes, usually heals without consequences. In rare cases, however, severe courses with circulatory shock can occur.

Allergic vasculitis is characterized by inflammation of small blood vessels. It can lead to various complications such as kidney failure, severe intestinal bleeding, mental disorders or strokes. Sometimes fatal outcomes occur. The prognosis depends on the severity and location of the vasculitis. Exogenous allergic alveolitis can be treated very well.

But that only applies if the specific trigger is found. Otherwise, the course often becomes chronic. The lung tissue can then be remodeled as part of pulmonary fibrosis, leading to long-term death. Furthermore, right heart strain is also possible due to increased blood pressure in the small bloodstream, which in severe cases causes shortness of breath and cardiac insufficiency.

When should you go to the doctor?

Type III allergies always require treatment by a doctor. Since this disease cannot heal on its own, the person affected should always consult a doctor. This is the only way to prevent further complications. A doctor should therefore be contacted as soon as the first symptoms and signs of this allergy appear. In the worst case, the disease can lead to the death of the person concerned if the internal organs are damaged.

A doctor should be consulted for this disease if the person affected suffers from skin problems after ingesting a certain substance. This leads to severe redness or itching, which can spread to the entire body. It is not uncommon for the type III allergy to also lead to fever or severe diarrhea, which has a very negative effect on the quality of life of those affected. If the symptoms are not treated, it can also lead to inflammation of the kidneys. Type III allergies can usually be diagnosed by a general practitioner or an allergist. For further treatment, a visit to a specialist is usually necessary.

Treatment & Therapy

Of course, given the breadth of these conditions, each subtype of type III allergy has its own therapy.

In the case of autoimmune diseases, in most cases the doctor tries to suppress the body’s immune system to such an extent that the formation of immune complexes decreases and the inflammation of the vessel walls decreases. Drugs such as cortisol or other immunosuppressants are used here.

In the event of an allergic reaction, as in serum sickness, the only option is to stop the supply of antigen immediately and provide symptomatic emergency therapy.


The following applies to allergic lung diseases: the longer the contact with the triggering dust, the further the disease progresses. Occupational safety measures are extremely important for later health in the professions concerned.


Type III allergy requires comprehensive follow-up care. After an allergic reaction, the doctor should be consulted immediately. The initial examination serves to clarify the symptoms and initiate therapy. The actual follow-up care begins once the patient has recovered from the allergic reaction.

First, the doctor talks to the patient to assess the severity of the allergy. The burden that the allergy has on the patient’s life is also important for the choice of follow-up treatment. The specialist doctor can carry out detailed examinations and, for example, initiate hyposensitization.

Type III allergy follow-up care also includes specific immunotherapy. After an allergic reaction, steps should be taken to alleviate or completely eliminate the allergy. The family doctor or allergist can put you in touch with a specialist center where patients receive the necessary therapy. The aftercare of a type III allergy is carried out by the general practitioner or an allergist. Depending on the symptoms and type of allergy, other specialists can be involved in the treatment if necessary.

You can do that yourself

Type III allergy can be treated using various self-help measures. The first thing to do is to avoid the triggering substances. Since this is not always possible in practice, a suitable emergency drug must also be available, which will quickly relieve the allergy symptoms in case of doubt.

Basically, a healthy lifestyle should be led with a balanced diet and plenty of exercise. This keeps the immune system fit and can counteract allergens more effectively. However, should an allergic reaction occur, the emergency doctor must be called or the patient taken to a hospital. Depending on the severity of the allergic reaction, rest or comprehensive medical treatment will suffice.

Type III allergy manifests itself in that the allergic reaction occurs with a significant time lag after contact with the triggering substance. Affected people should therefore check their diet closely and note any deviations with the time and date. The data can then be used to determine the trigger. If symptoms occur that indicate a mild allergic reaction, the allergy sufferer should drink a lot and take it easy for a day or two. If the symptoms do not go away on their own, it is advisable to see a doctor.

Type III Allergy