Are there almond allergies

These allergic reactions can range from a mild rash to severe breathing difficulties. Most people experience allergy symptoms just after a few hours of eating them. Read on to learn more about almond allergy symptoms and how to manage them. An almond allergy or intolerance is a set of symptoms brought on after being in contact with almonds. While most people can eat almonds in moderation with effects, those with an intolerance to almonds are likely to feel different levels of sickness after eating almonds.

One reason for an allergic reaction is because the body may identify almond proteins as foreign. This can happen when tiny particles leak into the bloodstream during digestion. This triggers an immune response which can cause inflammation. As with all food allergies, the severity and type of symptoms are different from person to person. Symptoms may also take up to 72 hours to appear. Symptoms involving the skin are usually the most typical food allergy reactions.

If you have an almond allergy, you may develop hives or an itchy rash after eating almonds. Most of the time, these symptoms will appear within an hour of exposure. Oral allergy syndrome another common reaction. It is another name for reactions involving the mouth. An itchy mouth or throat is one of the most common allergy symptoms.

Do not stand or walk. Many food allergies do not cause severe symptoms, but they can be life threatening in some people and should be taken seriously. Some people have negative or adverse reactions to food such as headache or bloating that are not caused by allergies. These can be caused by factors such as food poisoning, toxic reactions or food sensitivities intolerance.

Although these are not allergic reactions, they are often mistaken for allergies. Mild allergic symptoms that can occur before a severe allergic reaction include:. If you or a child in your care have experienced any of these symptoms after eating peanuts, tree nuts or seeds, the risk of having a severe reaction after eating that food is greater than usual.

Ask your doctor to refer you to a clinical immunology or allergy specialist. Diagnosing an allergy can be difficult. If you think you or a child in your care might have an allergy, keeping a record of symptoms can help you and your doctor to understand what is causing them.

Keep a diary that describes the symptoms, and when and where they occur. Your diary could include information about whether the symptoms occur:. Peanuts and tree nuts are among the most common foods to cause severe allergic reactions.

Severe allergic reaction anaphylaxis is life threatening. Symptoms of a severe allergic reaction include:. For all allergies, the immune system reacts to specific allergy trigger molecules allergens.

Your immune system, or that of a child in your care, produces antibodies that detect the allergen and cause inflammatory reactions and the release of a chemical called histamine. Histamine causes hives, hay fever and other allergic symptoms. The molecules that trigger your allergic reaction can be present in a range of foods, and you may have an allergic reaction to foods containing that molecule.

For this reason, some people are allergic to the same allergy trigger in cashews and pistachios. This is known as cross-reactivity. Speak to your doctor about cross-reactivity because it is difficult to predict. In addition to peanuts, a wide range of tree nuts can also cause allergic reactions in some people.

These include, but are not limited to:. The most common type of seed allergy is to sesame, although other types of seed, such as sunflower and poppy seeds, can also cause allergies. Allergic reactions to eating coconut, a large seed, are rare.

However, an allergic reaction contact dermatitis caused by contact with coconut, and cosmetics and products containing coconut, is more common. Peanut, tree nut and seed allergies are difficult to predict, so visit your doctor for an accurate diagnosis.

If you have allergic symptoms, visit your family doctor who will ask some questions about your allergic reactions. You can also discuss your record of your symptoms.

To diagnose your allergy, your doctor may refer you to a specialist doctor known as an allergist or clinical immunologist. Prevalence of self-reported tree nut allergy in Canada was 1. Lower rates were observed in Australian adults [ 12 ]. Due to cross-reactivity, data for individual nuts is more limited, though Wan and Chiu [ 13 ] reported that 2.

In the US, almonds are the third most common tree nut to cause allergy after walnuts and cashews [ 14 , 15 ]. In Europe, the prevalence of self-reported allergy to any nut was estimated to be 1. Hazelnut allergy was the most common tree nut allergy [ 20 ]. Prevalence data for almond allergy are almost exclusively available only for children.

It seems clear that tree nut allergy rates vary by geographical region and depend on the mix of nuts commonly consumed [ 21 ]. Geographical comparisons are difficult to make since country-based studies differ in the type of nut, age group and method of diagnosis [ 22 ]. It is believed that allergy to one type of nut is a risk factor for developing allergy to other types of nuts.

A recent investigation showed a cherry seed-derived spice, mahleb , is recognized by anti-almond antibodies including almond-allergic patient IgE [ 25 ]. The cross-reactivity between almond and mahleb , which is prepared from the kernels of a species of cherry, should be of particular concern to almond-allergic patients and attending medical personnel. Uotila et al. Cashew and pistachio, and pecan and walnut were the most widely seen cross-reactions.

Tree nut challenges are also frequently passed in patients with tree nut sensitization, and nearly all patients with peanut allergy and tree nut co-sensitization passed the challenge, thus calling into question the clinical relevance of cross-reactivity [ 27 ]. A recent study reported that household consumption of almond and peanut was related to development of sensitization to peanuts [ 28 ].

Primary allergy and sensitization to one tree nut or seed allergen IgE level low, generally young patients, ie cashew nut allergy ; 2. Primary sensitization and allergy to at least one tree nut or seed associated to cross-reactive IgE to another botanically related tree nut or seed i. Primary sensitization and allergy to at least one tree nut or seed and cross-reactive IgE to another botanically not closely related tree nut or seed i.

Primary sensitization to pollen and cross-reactive IgE birch-pollen related food allergy. The studies outlined above highlight the diversity of prevalence data and the limitations of sensitization as a measure of allergy. Both are factors that make risk factors for almond allergy very difficult to calculate. Almond proteins, including the major storage protein amandin, have been identified as allergens. Eight native almond Prunus dulcis allergens have been characterized according to their biochemical function as summarized in Table 1 [ 30 , 31 , 32 , 33 ].

Potential Almond Allergens [ 30 , 36 ]. Pru du 6 has been related to severe reactions to almond upon ingestion [ 35 ]. The Pru du 6 isoforms have been sequenced, cloned and screened for IgE binding in almond-allergic patient sera [ 36 ]. The results of these isoform studies showed that of the two isoforms, Pru du 6. Other conformational epitope mapping studies of Pru du 6 have been performed with a murine monoclonal antibody mAb 4C10 [ 37 ].

Polypeptides from Pru du 6 are highly resistant to different heat treatments during food processing, and the contamination of food with this allergen can lead to a significant risk for sensitized patients [ 38 ].

Pru du 6 was found to be sensitive to pepsin during simulated gastric digestion using an in vitro model of the gastrointestinal tract [ 39 ].

However, incorporation of almond flour into a food matrix, such as chocolate mousse or Victoria sponge cake, decreased the rate of Pru du 6 degradation by pepsin.

Immunoreactivity of almond polypeptides detected by dot blots and sandwich enzyme-linked immunosorbent assay ELISA retained better reactivity [ 39 ]. In a study by Holden et al. However, the IgE binding and the serological reactivity to these proteins did not imply any clinical symptoms, and further studies are needed. As a result, neither of these have been incorporated into the standard clinical nomenclature.

Pru du 5, also known as 60S Acidic Ribosomal Protein P2, has been described as an almond allergen [ 42 ]. The immunoreactivity with ELISA using pooled and individual serum from almond allergic individuals showed that the expressed Pru du 5 proteins possessed the ability to bind IgE antibodies.

However, further investigation is needed in order to classify Pru du 5 as a major allergen. Several methods have been developed for almond allergen detection, mainly based on immunochemical, DNA-based techniques, and mass spectrometry MSs [ 30 ]. Immunochemical methods have been used to detect allergens in food by precise binding between epitopes present on the target protein and an immunoglobulin.

These methods, primarily ELISAs, have become the standard for qualitative and quantitative detection of allergen in food products [ 43 , 44 ]. ELISA detects protein s and is sufficiently sensitive detection limits of parts per million , thus providing rapid assessments [ 43 ]. These tests provide rapid, versatile and reliable testing of almond allergens with a limit of detection LOD down to 0.

This is because Pru du 6 is water-soluble and has high thermal stability in foods [ 30 , 35 , 47 , 48 ]. ELISA successfully detected almond Pru du 6 residues in a wide variety of test foods including dark, milk and white chocolate, peanut butter, spices, cereal, cheese, ice cream, salt, cauliflower, powdered mango and others [ 49 ].

These data confirm that food matrix and extraction conditions affect immunoassays [ 50 ], in this case for Pru du 6 detection and quantification. This pulsed-light treatment may have application for reducing the allergenicity of specialty almond products like almond milk. The results indicated that Pru du 6 was present in all of the samples tested. Another study has reported the development of a sandwich ELISA using anti-almond soluble protein rabbit polyclonal antibodies as capture antibodies and murine-mAb as detection antibodies [ 53 ].

The assay did not register any cross-reactivity with the food matrices tested, suggesting the assay to be almond Pru du 6 specific. The assay could detect the presence of declared almond in the tested matched commercial samples.

Further, the assay reliably detected the presence of almonds in the laboratory-prepared food samples spiked with almond flour. A recent publication by Su et al. The results demonstrated that Pru du 6 immunoreactivity is stable in processed almond seeds and could be detected in whole raw and processed blanched, sliced, dry-roasted, flour and defatted flour almonds for several years.

These are based on the same principle as ELISA but are simpler and faster about 10 min and used by industry for rapid allergen screening [ 30 ]. The results are primarily qualitative or semi-quantitative so the drawbacks with this method are the potential for false negatives and lack of quantitative data.

However, these tests provide quick on-site detection of almond allergens within minutes. For example, detection down to 1 ppm in 10 min. Immunoblotting constitutes a confirmatory test for the presence of almond allergens in food. Immunoblotting can detect almond protein in chocolate with a LOD of 5 ppm [ 55 ]. A novel immunoassay test system was developed to detect modified allergen residues present in almond, cashew, coconut, hazelnut and soy-based non-dairy beverages [ 56 ].

The tests showed robust detection capabilities, a sensitivity of 1 ppm and selectivity values of 3—5 ppm. These methods do not directly target protein allergens but rather amplify the gene fragment encoding for the allergen protein by means of polymerase chain reaction PCR , either as qualitative endpoint PCR or as quantitative real-time PCR assays. DNA-based methods take advantage of the greater thermal stability of DNA molecules compared to proteins.

Methods combining both PCR and ELISA have been developed for the detection of food allergens to fit standards for potential labeling requirements [ 58 ]. However, since PCR tests do not detect proteins from their source, their use in food allergy risk assessment is confined [ 59 ]. The MS methods provide specific information on the identification of allergenic proteins in almonds [ 60 ]. These methods rely on the primary sequence of proteins and peptides with data on molecular mass and protein identification algorithms.

The LOD for specific almond allergens is 3 ppm in bread [ 30 ]. Advanced MS techniques have recently been used for the isolation and characterization of a potentially allergenic Pru du 3 lipid transfer protein in almond: the full sequence was identified with LC-ESI-Orbitrap-MS and consisted of 92 amino acids, with a predicted molecular weight of The use of MS methods for the qualitative and quantitative detection of allergenic food proteins has recently been further explored [ 62 ].

MS methods can also detect multiple food allergens simultaneously [ 63 ], with a sensitivity similar to ELISA methods. Advances in the allergen-microarray technology for diagnosis and monitoring of allergy have recently been discussed through the use of a MeDALL allergen-chip [ 64 ]. The MeDALL allergen-chip has been developed for the specific and sensitive monitoring of IgE and IgG reactivity profiles towards more than allergen molecules in sera collected in European birth cohorts.

MeDALL is a European research program in which allergen microarray technology is used for the monitoring of the development of allergic disease in childhood, to draw a geographic map of the recognition of clinically relevant allergens in different populations and to establish reactivity profiles, which are associated with and predict certain diseases. Other methods, such as the Adenosine Tri-Phosphate ATP test and total protein tests, are used by the food industry [ 43 ].

These methods are useful tools for monitoring the cleaning process, but do not provide any quantitative detection for risk assessment. Thresholds are minimum allergen concentrations present in a food which trigger a reaction in a sensitized person. It is very challenging to establish the amount of an allergenic protein that poses a health risk. Significant amounts of such data are needed in order to provide population-based threshold data.

Since , several clinical investigations have been performed with low dose challenges in order to provide data for modeling purposes [ 66 , 67 ]. The EuroPrevall project, the largest multicenter European study on food allergy, aimed to develop effective management strategies in food allergy through a multidisciplinary integrated approach [ 68 ].

Threshold dose distributions for 5 major allergenic foods in the European populations were defined [ 69 ]. Low-dose, double-blind, placebo-controlled food challenges DBPCFCs were undertaken with commercially available food ingredients peanut, hazelnut, celery, fish and shrimp blinded into common matrices.

Standardized DBPCFCs were also used to confirm thresholds data for milk, egg, fish, shrimp, peanut, hazelnut, celeriac, apple and peach [ 68 ]. Currently, no threshold doses are available for almonds. Food matrix and other extrinsic factors could affect threshold doses. It is becoming clear that, as the major mucosal surface comes into contact with the food we eat, the mucosal barrier of the gastrointestinal tract plays an important role in both the development of food allergy sensitization and manifestation of an allergic reaction elicitation.

Therefore, the effects of digestion may help explain and predict effects of the food matrix on the delivery of allergen to the mucosal surface, including how the food matrix may modulate allergic reactions [ 70 , 71 ]. Food processing also affects allergenic potential [ 72 , 73 ]. The types of processing implicated in influencing allergenic properties are the following: heating thermal processing , fermentation including endogenous enzymatic hydrolysis, enzymatic and acid hydrolysis, physical treatment such as high pressure processing or extrusion , the use of preservatives, changes in pH, or combination of any two or more of these [ 23 , 74 ].

In almonds, blanching and roasting did not have any effect on the allergenicity of Pru du 6, confirming the heat stability of this protein. However, using immunoblotting with sera from almond allergic patients, blanching and roasting reduced the IgE-binding of a 15—17 KDa band, which may be Pru du 1 [ 38 , 75 ]. De Leon et al. The difference might be due to the small size of sample tested in the studies. Su et al. However, Dhakal et al. The effects of dry and moist heat, autoclave sterilization and high-pressure treatment on the biochemical and immunological properties were also evaluated [ 79 ].

All stakeholders agree that precautionary allergen labelling must reflect actual risk and should indicate the likely unintended presence of an allergen in a consumed portion of a food product that is at or above a reference dose [ 80 ].

There is a general duty of care on the food industry and the obligations in European Union EU legislation to reduce and manage the presence of allergens.

While there is an EU regulation for allergen present as an ingredient, this is not the case for the unintended presence of allergens [ 81 ]. There is an urgent requirement for effective communication between healthcare professionals, patient organizations, food industry and regulators in order to develop a better approach to protect consumers with food allergies [ 82 ].

In this review, we have looked at the evidence for the prevalence to almond allergy, which shows that almond allergy is rare. Although almond has 4 primary allergens, of which Pru du 6 is the most studied, there is little evidence for the efficacy of component-resolved diagnosis.

In terms of detection, the immunoassay-based methods are still the most widely used and seemingly the most reliable in food-based products, although the potential of MS methods might lead to promising sensitivities once more almond proteins have been sequenced and the available database updated accordingly.

Our primary conclusion is that population-based threshold data is needed in order to provide effective risk assessment and consumer advice. Thus, more studies need to be undertaken with the relevant allergic groups so that we can move beyond the current precautionary labelling. National Center for Biotechnology Information , U. Journal List Nutrients v.

Published online Nov 8. Mackie 2. Alan R. A Find articles by Alan R.