Peanut allergy

# What is a peanut allergy? Peanut allergy is a widespread food allergy with a high prevalence, especially in Western countries. It poses a serious health risk as it can trigger severe allergic reactions in those affected by even the smallest amounts. These reactions are caused by a hypersensitivity of the immune system to certain proteins in peanuts. The immune system reacts to these proteins as if they were harmful intruders and forms immunoglobulin E antibodies (IgE), which set off an allergic cascade. Despite intensive research, the exact cause of peanut allergy is not yet fully understood. However, it is known that both genetic and environmental factors play a role. The prevalence of this allergy appears to have increased in recent decades, possibly due to changes in dietary habits and environmental influences. At the same time, research has made significant progress in understanding the immunological mechanisms underlying peanut allergy, contributing to the development of new diagnostic and treatment methods. # Immunological mechanisms and symptoms Peanut allergy is based on a specific immune reaction in which the immune system misinterprets the proteins contained in the peanut as threatening. Upon contact, whether through ingestion, inhalation or skin contact, immunoglobulin E antibodies (IgE) are released, which bind to mast cells and basophils. This releases inflammatory mediators such as histamine, which can cause a variety of symptoms. These range from localized reactions such as itching and skin rash to severe systemic reactions such as shortness of breath, drop in blood pressure and shock or anaphylaxis, which require immediate medical treatment. Due to the potential severity of these reactions, those affected and those around them must be particularly careful to avoid accidental exposure, especially in children, where the allergy is often discovered late and can have a significant impact on quality of life. > ## Good to know > > Peanuts are botanically a legume and not a true nut, making them a surprising source of allergies, although they are often treated in the same category as true nuts. # Diagnosis and prevention Peanut allergy is usually diagnosed by a combination of medical history, skin prick testing, specific IgE testing in the blood and sometimes oral challenge testing under medical supervision. As a peanut allergy cannot be cured, the primary treatment strategy is to strictly avoid peanuts and peanut-containing products. People with a peanut allergy should always carry an emergency kit with antihistamines and adrenaline auto-injectors so that they can react quickly in the event of accidental exposure. Raising awareness of the issue and food labeling are also important measures to prevent severe allergic reactions. # Quality of life with a peanut allergy A peanut allergy not only has a health impact, but also a psychosocial impact on those affected and their families. The constant pressure to avoid allergic reactions can lead to considerable restrictions in everyday life, especially when eating outside the home. Many sufferers develop anxiety disorders or social isolation due to fear of unintentional exposure. It is therefore important that those affected and their families receive psychosocial support and develop strategies for dealing with the allergy in order to maintain quality of life and minimize possible psychological stress. # What do genetics have to do with it? The mechanism by which specific SNPs such as rs7192 in the HLA-DRA gene and rs9275596 in the HLA-DQB1|HLA-DQA2 system contribute to peanut allergy is closely linked to the function of the immune system. The HLA-DRA gene encodes a part of the HLA-DR molecule that plays a central role in the presentation of peptides to T cells. This presentation is crucial for the recognition of allergens by the immune system. The SNP rs7192 in the HLA-DR gene can affect the structure and function of the HLA-DR molecule, thereby altering the way in which peptides - including peanut proteins - are presented to T cells. An altered presentation can lead to the immune system recognizing the peanut proteins as foreign and triggering an excessive immune response that leads to allergic reactions. The SNP rs9275596 is located near the genes HLA-DQB1 and HLA-DQA2, which together form the HLA-DQ molecule. Like HLA-DR molecules, HLA-DQ molecules are responsible for the presentation of peptides to T cells. Variations in the HLA-DQB1 and HLA-DQA2 genes influence the ability to bind and present allergens. A specific variant of the SNP rs9275596 can alter the affinity and specificity of the HLA-DQ molecule for certain peptides, leading to a different presentation of peanut proteins. This in turn increases the likelihood that the immune system will develop an allergic reaction to these proteins.