Oral allergy syndrome

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Oral allergy syndrome (Pollen-Food Allergy)
Specialty Immunology

Oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFAS) is a type of allergy classified by a cluster of allergic reactions in the mouth and throat in response to eating certain (usually fresh) fruits, nuts, and vegetables. It typically develops in adults with hay fever. [1] It is not usually serious. [2]

Contents

OAS is the result of cross-reactivity between antigens of tree or weed pollen and antigens found in certain fruits and vegetables. Therefore, OAS is only seen in people with seasonal pollen allergies, and mostly people who are allergic to tree pollen. [3] It is usually limited to ingestion of uncooked fruits or vegetables. [3] In adults, up to 60% of all food allergic reactions are due to cross-reactions between foods and inhalative allergens. [4]

OAS is a class II allergy where the body's immune system produces IgE antibodies against pollen; in OAS, these antibodies also bind to (or cross-react with) other structurally similar proteins found in botanically related plants. This differs from class 1 food allergy where sensitisation to the protein occurs in the GI tract, and is produced as a result of exposure to the food itself. [5]

OAS can occur any time of the year, but is most prevalent during the pollen season. Individuals with OAS usually develop symptoms within minutes of eating the food. [6]

Signs and symptoms

Individuals with OAS may have any of a number of allergic reactions that usually occur very rapidly, within minutes of eating a trigger food. The most common reaction is an itching or burning sensation in the lips, mouth, ear canal, or pharynx. Sometimes other reactions can be triggered in the eyes, nose, and skin. Swelling of the lips, tongue, and uvula, and a sensation of tightness in the throat may be observed. Once the allergen reaches the stomach, it is broken down by the acid, and the allergic reaction does not progress further. [7] : 405  The natural course of the disease is that it usually persists. [7] : 407 

If an affected person swallows the raw food, and the allergen is not destroyed by the stomach acids, it is likely that there will be a reaction from histamine release later in the gastrointestinal tract. Vomiting, diarrhea, severe indigestion, or cramps may occur. [6] Rarely, OAS may be severe and present as wheezing, vomiting, hives, low blood pressure, [8] or anaphylaxis. [9]

Development, causes

A person with an allergic disposition is sensitized to allergenic pollen proteins through the respiratory route can develop an allergy to heat labile food proteins (for example profilins) in certain fruits and vegetables, which cross-react with pollen proteins. [7] : 409 

OAS produces symptoms when an affected person eats certain fruits, vegetables, and nuts. Some individuals may only show allergy to one particular food, and others may show an allergic response to many foods. [1] [ dead link ]

Individuals with an allergy to tree pollen may develop OAS to a variety of foods. While the tree pollen allergy has been worked out, the grass pollen is not well understood. Furthermore, some individuals have severe reactions to certain fruits and vegetables that do not fall into any particular allergy category. When tropical foods initiate OAS, allergy to latex may be the underlying cause. [10]

Because the allergenic proteins associated with OAS are usually destroyed by cooking, most reactions are caused by eating raw foods. [7] The main exceptions to this are celery and nuts, which may cause reactions even after being cooked. [11]

Cross reactions

Allergies to a specific pollen are usually associated with OAS reactions to other certain foods. For instance, an allergy to ragweed is associated with OAS reactions to banana, watermelon, cantaloupe, honeydew, zucchini, kiwifruit, and cucumber. This does not mean that everyone with an allergy to ragweed will experience adverse effects from all or even any of these foods. Reactions may be associated with one type of food, with new reactions to other foods developing later. However, reaction to one or more foods in any given category does not necessarily mean a person is allergic to all foods in that group.[ citation needed ]

Diagnosis

The person typically already has a history of atopy and an atopic family history. Eczema, otolaryngeal symptoms of hay fever or asthma will often dominate leading to the food allergy being unsuspected. Often well-cooked, canned, pasteurized, or frozen food offenders cause little to no reaction due to denaturation of the cross-reacting proteins, [9] causing delay and confusion in diagnosis as the symptoms are elicited only to the raw or fully ripened fresh foods. Correct diagnosis of the allergen types involved is critical. Those with OAS may be allergic to more than just pollen. Oral reactions to food are often mistakenly self-diagnosed by patients as caused by pesticides or other contaminants. Other reactions to food—such as lactose intolerance and intolerances which result from a patient being unable to metabolize naturally occurring chemicals (e.g., salicylates and proteins) in food—need to be distinguished from the systemic symptoms of OAS.[ citation needed ]

Testing

Many people are unaware that they have OAS. However, if swelling, tingling or pain develops while eating certain foods, it is wise to see an allergy specialist. Before a diagnosis can be made, it is best to keep a food diary. This is important as the physician can then perform an allergy test. A comprehensive history is obtained so that random testing is avoided. The diagnosis of OAS may involve skin prick tests, blood tests, patch tests or oral challenges.[ citation needed ]

Exams

To confirm OAS, the suspected food is consumed in a normal way. The period of observation after ingestion and symptoms are recorded. If other factors such as combined foods are required, this is also replicated in the test. For example, if the individual always develops symptoms after eating followed by exercise, then this is replicated in the laboratory.[ citation needed ]

Treatment

OAS must be managed in conjunction with the patient's other allergies, primarily the allergy to pollen. The symptom severity may wax and wane with the pollen levels. Published pollen counts and seasonal charts are useful but may be ineffective in cases of high wind or unusual weather, as pollen can travel hundreds of kilometers from other areas. In addition, patients are advised to avoid the triggering foods, particularly nuts. Peeling or cooking the foods has been shown to eliminate the effects of some allergens such as mal d 1 (apple), but not others such as celery or strawberry. In the case of foods such as hazelnut, which have more than one allergen, cooking may eliminate one allergen but not the other.[ citation needed ]

Antihistamines may also relieve the symptoms of the allergy by blocking the immune pathway. Persons with a history of severe anaphylactic reaction may carry an injectable emergency dose of epinephrine (such as an EpiPen). Oral steroids may also be helpful. Allergy immunotherapy has been reported to improve or cure OAS in some patients. Immunotherapy with extracts containing birch pollen may benefit those with apple or hazelnut related to birch pollen-allergens. Even so, the increase in the amount of apple/hazelnut tolerated was small (from 12.6 to 32.6 g apple), and as a result, a patient's management of OAS would be limited. [16]

See also

Related Research Articles

<span class="mw-page-title-main">Allergy</span> Immune system response to a substance that most people tolerate well

Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions.

An allergen is an otherwise harmless substance that triggers an allergic reaction in sensitive individuals by stimulating an immune response.

<span class="mw-page-title-main">Ragweed</span> Genus of plants

Ragweeds are flowering plants in the genus Ambrosia in the aster family, Asteraceae. They are distributed in the tropical and subtropical regions of the Americas, especially North America, where the origin and center of diversity of the genus are in the southwestern United States and northwestern Mexico. Several species have been introduced to the Old World and some have naturalized and have become invasive species. In Europe, this spread is expected to continue, due to ongoing climate change.

<span class="mw-page-title-main">Allergic rhinitis</span> Nasal inflammation due to allergens in the air

Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis.

<span class="mw-page-title-main">Rhinitis</span> Irritation and inflammation of the mucous membrane inside the nose

Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip.

<span class="mw-page-title-main">Food allergy</span> Hypersensitivity reaction to a food

A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.

<span class="mw-page-title-main">Latex allergy</span> Medical condition

Latex allergy is a medical term encompassing a range of allergic reactions to the proteins present in natural rubber latex. It generally develops after repeated exposure to products containing natural rubber latex. When latex-containing medical devices or supplies come in contact with mucous membranes, the membranes may absorb latex proteins. In some susceptible people, the immune system produces antibodies that react immunologically with these antigenic proteins. Many items contain or are made from natural rubber, including shoe soles, pen grips, hot water bottles, elastic bands, rubber gloves, condoms, baby-bottle nipples, and balloons; consequently, there are many possible routes of exposure that may trigger a reaction. People with latex allergies may also have or develop allergic reactions to some fruits, such as bananas.

<span class="mw-page-title-main">Allergic conjunctivitis</span> Medical condition

Allergic conjunctivitis (AC) is inflammation of the conjunctiva due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist of redness, edema (swelling) of the conjunctiva, itching, and increased lacrimation. If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis (ARC).

<span class="mw-page-title-main">Allergen immunotherapy</span> Medical treatment for environmental allergies

Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for environmental allergies and asthma. Immunotherapy involves exposing people to larger and larger amounts of allergens in an attempt to change the immune system's response.

<span class="mw-page-title-main">Peanut allergy</span> Type of food allergy caused by peanuts

Peanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, because peanuts are legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected.

<span class="mw-page-title-main">Soy allergy</span> Type of food allergy caused by soy

Soy allergy is a type of food allergy. It is a hypersensitivity to ingesting compounds in soy, causing an overreaction of the immune system, typically with physical symptoms, such as gastrointestinal discomfort, respiratory distress, or a skin reaction. Soy is among the eight most common foods inducing allergic reactions in children and adults. It has a prevalence of about 0.3% in the general population.

<span class="mw-page-title-main">Milk allergy</span> Type of food allergy caused by milk

Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. Symptoms may take hours to days to manifest, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon. However, rapid anaphylaxis is possible, a potentially life-threatening condition that requires treatment with epinephrine, among other measures.

<span class="mw-page-title-main">Egg allergy</span> Type of food allergy caused by eggs

Egg allergy is an immune hypersensitivity to proteins found in chicken eggs, and possibly goose, duck, or turkey eggs. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus.

<span class="mw-page-title-main">Tree nut allergy</span> Medical condition

A tree nut allergy is a hypersensitivity to dietary substances from tree nuts and edible tree seeds causing an overreaction of the immune system which may lead to severe physical symptoms. Tree nuts include almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, pecans, pistachios, shea nuts and walnuts.

<span class="mw-page-title-main">Wheat allergy</span> Medical condition

Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was estimated to be 0.21% in a 2012 study in Japan.

Oleosins are structural proteins found in vascular plant oil bodies and in plant cells. Oil bodies are not considered organelles because they have a single layer membrane and lack the pre-requisite double layer membrane in order to be considered an organelle. They are found in plant parts with high oil content that undergo extreme desiccation as part of their maturation process, and help stabilize the bodies.

A fruit allergy is a food allergy. Fruit allergies make up about ten percent of all food-related allergies.

<span class="mw-page-title-main">Fish allergy</span> Type of food allergy caused by fish

Fish allergy is an immune hypersensitivity to proteins found in fish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Fish is one of the eight common food allergens which are responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.

<span class="mw-page-title-main">Shellfish allergy</span> Type of food allergy caused by shellfish

Shellfish allergy is among the most common food allergies. "Shellfish" is a colloquial and fisheries term for aquatic invertebrates used as food, including various species of molluscs such as clams, mussels, oysters and scallops, crustaceans such as shrimp, lobsters and crabs, and cephalopods such as squid and octopus. Shellfish allergy is an immune hypersensitivity to proteins found in shellfish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Shellfish is one of the eight common food allergens, responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.

<span class="mw-page-title-main">Sesame allergy</span> Food allergy caused by sesame seeds

A food allergy to sesame seeds has prevalence estimates in the range of 0.1–0.2% of the general population, and are higher in the Middle East and other countries where sesame seeds are used in traditional foods. Reporting of sesame seed allergy has increased in the 21st century, either due to a true increase from exposure to more sesame foods or due to an increase in awareness. Increasing sesame allergy rates have induced more countries to regulate food labels to identify sesame ingredients in products and the potential for allergy. In the United States, sesame became the ninth food allergen with mandatory labeling, effective 1 January 2023.

References

  1. 1 2 "Oral Allergy Syndrome". Canadian Food Inspection Agency. January 2000. Retrieved 2008-01-25.[ dead link ]
  2. ↑ "Food allergy". NHS . 2017-10-19. Retrieved 2024-05-03.
  3. 1 2 Papadakis, Maxine A.; McPhee, Stephen J.; Rabow, Michael W. (2017-09-11). Current Medical Diagnosis and Treatment 2018, 57th Edition. McGraw Hill Professional. p. 885. ISBN   9781259861499.
  4. ↑ Werfel, Thomas (2008). "Food allergy". Journal der Deutschen Dermatologischen Gesellschaft. 6 (7): 573–583. doi:10.1111/j.1610-0387.2008.06778.x. PMID   18611176. S2CID   44901435.
  5. ↑ Carlson, Geoffrey; Coop, Christopher (Nov 2019). "Pollen food allergy syndrome (PFAS): A review of current available literature". Annals of Allergy, Asthma & Immunology. 123 (4): 359–365. doi:10.1016/j.anai.2019.07.022. PMID   31376490.
  6. 1 2 Pong, Anthony Ham (June 2000). "Oral Allergy Syndrome". Allergy/Asthma Information Association (AAIA) Newsletter.
  7. 1 2 3 4 5 6 7 Cosme-Blanco, Wilfredo; Arroyo-Flores, Erving; Ale, Hanadys (2020-08-01). "Food Allergies" (PDF). Pediatrics in Review. 41 (8): 403–415. doi:10.1542/pir.2019-0037. ISSN   0191-9601. PMID   32737253. S2CID   220872242.
  8. ↑ "Oral Allergy Syndrome". oralallergy.net. Archived from the original on 2012-10-05. Retrieved 2010-01-26.
  9. 1 2 More, D. (April 28, 2007). "Oral Allergy Syndrome". About.com. Retrieved 2008-01-25.
  10. ↑ "Oral Allergy Syndrome". Asthma and Allergy Foundation of America. Archived from the original on 2015-09-05. Retrieved 2015-05-26.
  11. ↑ Kashyap, Roopashri Rajesh; Kashyap, Rajesh Shanker (2015). "Oral Allergy Syndrome: An Update for Stomatologists". J Allergy (Cairo). 2015: 1–6. doi: 10.1155/2015/543928 . PMC   4655061 . PMID   26633978.
  12. ↑ "General Information for Banana". Informall. 18 Oct 2006. Archived from the original on 8 March 2018. Retrieved 27 Sep 2011.
  13. ↑ Cadot, P.; Kochuyt, A.-M.; Van Ree, R.; Ceuppens, J.L. (2003). "Oral Allergy Syndrome to Chicory Associated with Birch Pollen Allergy". International Archives of Allergy and Applied Immunology. 131 (1): 19–24. doi:10.1159/000070430. PMID   12759485. S2CID   42538679.
  14. 1 2 Antico, A.; Zoccatelli, G.; Marcotulli, C.; Curioni, A. (2003). "Oral Allergy Syndrome to Fig". International Archives of Allergy and Applied Immunology. 131 (2): 138–142. doi:10.1159/000070929. PMID   12811022. S2CID   19077935.
  15. 1 2 "It Might Be Your Allergies". Rush University Medical Center.
  16. ↑ Bucher, X.; Pichler, W. J.; Dahinden, C. A.; Helbling, A. (December 2004). "Effect of tree pollen specific, subcutaneous immunotherapy on the oral allergy syndrome to apple and hazelnut". Allergy. 59 (12): 1272–1276. doi:10.1111/j.1398-9995.2004.00626.x. PMID   15507095. S2CID   38141361.
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