Dorothy FarrarType III allergy
Type III allergies are characterized by the fact that antibodies are formed against soluble antigens. The fact that the antibodies bind to the antigens creates so-called immune complexes. Therefore, type III allergies are also referred to as allergies of the antibody-dependent immune complex type.
What is a type III allergy?
The most important characteristic of type III allergies is the formation of antibodies against soluble antigens. The antibodies and antigens are multivalent. This means that they have several binding sites and can also bind several antibodies and antigens. This enables the formation of immune complexes, which is very characteristic of type III allergies.
These immune complexes become problematic when they either deposit in capillaries and thus clog them and when they trigger inflammation-activating complement activation. According to the type of triggering antigens, type III allergies are distinguished from the Arthurian type and the serum sickness type. The Arthurian type is caused by drugs or microbial components, the serum disease type by foreign proteins, insecticides, enzymes of bacteria or drugs.
Causes
The causes of type III allergies can be manifold and have not yet been fully understood. However, at least in industrialized countries, a significant increase in allergic diseases has been registered. A proven reason for the development of allergies is genetic predisposition. Children whose mother or father already have an allergy themselves have a greatly increased risk of developing an allergy. If both parents are allergy sufferers, the risk is even higher. However, not a single gene is responsible for the allergy tendency, rather several factors play together.
Also, the various symptoms that an allergy shows depend on the genetic predisposition. In part, excessive hygiene and increasing environmental pollution are also blamed for the increased occurrence of allergies. Due to too much hygiene, especially in early childhood, the immune system comes into too little contact with foreign substances. This increases the likelihood of hypersensitivity reactions.
Symptoms and course
Typical symptoms of type III allergy:
In the case of a type 3 allergy, it takes a few hours for externally visible symptoms to appear. After contact with the allergen in question, the described immune complexes are formed from antibodies and antigens. They can either be cell-like or circulate dissolved in the blood. As with type II, this leads to an activation of the complement system. This causes leukocytes to phagocyte the complexes, i.e. to eat them.
In addition, the leukocytes are influenced to release cytotoxic enzymes. In the Arthurian reaction, either an allergic vascular inflammation occurs, in the case of already existing systemic lupus erythematosus to a kidney ball inflammation or to a local Arthurian reaction. The local Arthurian reaction is characterized by localized redness and swelling. Furthermore, it can lead to ulcers, bleeding and death of skin areas.
Serum sickness occurs about four to ten days after administration of a foreign immune serum. Signs are inflammation, water retention and hives at the site of the injection. Sometimes fever, skin reactions affecting the entire body and lymph node inflammation also occur.
Diagnosis
The diagnosis of a type III allergy is made by laboratory chemical detection of the specific immune complexes or antibodies in the blood. For example, in autoimmune diseases that are based on a reaction in the sense of a type 3 allergy, the detection of autoantibodies is a common and reliable method.
Treatment and therapy
Since type III allergies include many diseases and symptoms, no general treatment approach can be given. Each individual subtype of type III allergy has a specific and most suitable treatment method. In autoimmune diseases, which belong to allergies of type 3, drugs are usually used that suppress the body’s immune system. As a result, significantly fewer immune complexes are formed, which in turn reduces allergic vascular wall inflammation and other symptoms.
For this purpose, drugs such as cortisone and other immunosuppressants are used. In the case of allergic reactions caused by certain allergens, such as serum sickness, the only treatment option is to immediately stop the allergen intake and treat the symptoms of the allergy. If an allergy to certain substances such as medication is already known, the allergen to which hypersensitivity is reacted must be consistently avoided, as any renewed contact causes the allergy to recur.
Prevention
Type III allergies can hardly be prevented. If necessary, an attempt can be made to avoid risk factors such as excessive hygiene. However, since this is difficult to do and genetic and other factors also play a very important role in the development of a type III allergy, there is no guaranteed successful prophylaxis. However, if the presence of a type III allergy is already known, then all substances to which an allergic reaction occurs must be avoided at all costs.
Otherwise, allergic symptoms will always break out again. Above all, avoiding allergens makes sense because there is always a risk of so-called sensitization. This means that the symptoms associated with the allergic reaction get worse with each new contact with the allergen.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.