The Oral allergy syndrome (OAS) is a - usually mild - form of food allergy. Typically, the symptoms only occur in the mouth and throat area.
The symptoms usually occur within minutes after eating certain fruits, some vegetables, some nuts or shellfish. In some foods a reaction only takes place if they are uncooked (fruits and raw vegetables). This is because when heated, the allergenic proteins by denaturation can lose their structure. Even with pickle or freeze this effect is on. However, this is not always the case. For example, heating at no influence nuts. Usually, the allergy is limited to one or a few types of food. Later, the reactions may also spread to other foods. The allergic reaction is usually limited to mild symptoms such as swelling, itching and redness in and around the mouth. Oral allergy syndrome is also called pollen-related food allergy or pollen-food cross-reactive called reactions. However, these are less suitable terms, because it does not distinguish between the OAS and pollen allergies / hay fever.
OAS is an overreaction of the immune system to food. The immune system thereby making IgE antibodies. The complaints arise not only when the allergen is absorbed into the bloodstream, but already after contact with the mucous membrane of the lips, mouth or esophagus. The reaction occurs therefore very quickly, usually within a few minutes. OAS is a syndrome that often shows a cross allergic reaction to pollen. It happens often in combination with hay fever. In a cross allergy is an allergic reaction to different substances with similar epitope.
.jpg "Oral Allergy Syndrome (OAS)")
The symptoms are generally mild, and act where the allergen comes into contact with the mucous membrane. The symptoms vary and may include:
These symptoms quickly, but also disappear quickly.
Typical of the OAS is that the phenomena confined to the mouth and throat area. However, they can later develop into symptoms such as abdominal pain, urticaria (hives), atopic allergy symptoms such as asthma and atopic dermatitis and even anaphylaxis.
Food allergy is usually triggered by protein particles. The atomic chains of large protein molecules are generally folded and wrapped together to form a protein structure. Where certain strands come together to nodes (epitopes) arise where antibodies can "docking" and cause an allergic reaction.
By heating, freezing or action by inmaakzuur these epitopes may be destroyed. If an allergen for its operation does not depend on the spatial structure of the allergenic protein as after the preparation still has its original shape, or recovers, it may be still caused OAS. Of apple, carrot and celery is known that cooking is active against OAS, but a study of B. Bohle showed that these foods then still be able to promote the generation of T-cells and thereby to worsen a present atopic eczema.
A study of Amlot et al indicated that predicts a positive prick test with high probability oral allergy syndrome. This in contrast to the more severe symptoms such as asthma, hives, eczema or migraine (without OAS), wherein the puncture test has a very low sensitivity. Also, the RAST test and the CAST ELISA test can be used to demonstrate to the OAS, although these are less accurate than the skin prick test. Further, also the medical history of the patient of interest.
The symptoms usually occur within minutes after eating certain fruits, some vegetables, some nuts or shellfish. In some foods a reaction only takes place if they are uncooked (fruits and raw vegetables). This is because when heated, the allergenic proteins by denaturation can lose their structure. Even with pickle or freeze this effect is on. However, this is not always the case. For example, heating at no influence nuts. Usually, the allergy is limited to one or a few types of food. Later, the reactions may also spread to other foods. The allergic reaction is usually limited to mild symptoms such as swelling, itching and redness in and around the mouth. Oral allergy syndrome is also called pollen-related food allergy or pollen-food cross-reactive called reactions. However, these are less suitable terms, because it does not distinguish between the OAS and pollen allergies / hay fever.
Causes of the oral allergy syndrome (OAS)
OAS is an overreaction of the immune system to food. The immune system thereby making IgE antibodies. The complaints arise not only when the allergen is absorbed into the bloodstream, but already after contact with the mucous membrane of the lips, mouth or esophagus. The reaction occurs therefore very quickly, usually within a few minutes. OAS is a syndrome that often shows a cross allergic reaction to pollen. It happens often in combination with hay fever. In a cross allergy is an allergic reaction to different substances with similar epitope.
Symptoms of oral allergy syndrome (OAS)
The symptoms are generally mild, and act where the allergen comes into contact with the mucous membrane. The symptoms vary and may include:
- itching in the mouth, palate and throat, into the ears
- irritation and blisters in the mouth
- swelling of the lips, palate, tongue, or glottis
- tightness in the throat
These symptoms quickly, but also disappear quickly.
Typical of the OAS is that the phenomena confined to the mouth and throat area. However, they can later develop into symptoms such as abdominal pain, urticaria (hives), atopic allergy symptoms such as asthma and atopic dermatitis and even anaphylaxis.
Food processing
Food allergy is usually triggered by protein particles. The atomic chains of large protein molecules are generally folded and wrapped together to form a protein structure. Where certain strands come together to nodes (epitopes) arise where antibodies can "docking" and cause an allergic reaction.
By heating, freezing or action by inmaakzuur these epitopes may be destroyed. If an allergen for its operation does not depend on the spatial structure of the allergenic protein as after the preparation still has its original shape, or recovers, it may be still caused OAS. Of apple, carrot and celery is known that cooking is active against OAS, but a study of B. Bohle showed that these foods then still be able to promote the generation of T-cells and thereby to worsen a present atopic eczema.
Testing for oral allergy syndrome
A study of Amlot et al indicated that predicts a positive prick test with high probability oral allergy syndrome. This in contrast to the more severe symptoms such as asthma, hives, eczema or migraine (without OAS), wherein the puncture test has a very low sensitivity. Also, the RAST test and the CAST ELISA test can be used to demonstrate to the OAS, although these are less accurate than the skin prick test. Further, also the medical history of the patient of interest.