Cross-reactivity between fruit and vegetables

Vegetable foods are the most frequent cause of food allergy after the age of 5 years. The most commonly implicated foods are fruit and dried fruits, followed in Spain by legumes and fresh garden produce. In patients allergic to fruit and garden produce, multiple sensitizations to other vegetable products, whether from the same family or taxonomically unrelated, are frequent, although they do not always share the same clinical expression. Furthermore, more than 75 % of these patients are allergic to pollen, the type of pollen varying in relation to the aerobiology of the area. The basis of these associations among vegetable foods and with pollens lies in the existence of IgE antibodies against "panallergens", which determines cross-reactivity. Panallergens are proteins that are spread throughout the vegetable kingdom and are implicated in important biological functions (generally defense) and consequently their sequences and structures are highly conserved. The three best-known groups are allergens homologous to Bet v 1, profilins, and lipid transfer proteins (LTP). Allergens homologous to Bet v 1 (major birch pollen allergen) constitute a group of defense proteins (PR-10), with a molecular weight of 17 kDa, which behave as major allergens in patients from northern and central Europe with allergy to vegetables associated with birch pollen allergy. In these patients, the primary sensitization seems to be produced through the inhalation route on exposure to birch pollen. The symptomatology characteristically associated with sensitization to this family of allergens is oral allergy syndrome (OAS). Profilins are highly conserved proteins in all eukaryotic organisms and are present in pollen and a wide variety of vegetable foods. They have a molecular weight of 14 kDa and present a high degree of structural homology as well as marked cross-reactivity among one another. The presence of anti-profilin IgE broadens the spectrum of sensitizations to vegetable foods detected through skin tests and/or in vitro tests but whether it correlates with the clinical expression of food allergy is unclear.LTPs are the most commonly implicated allergens in allergy to Rosaceae fruits in patients from the Mediterranean area without birch pollen sensitization. LTPs are a family of 9kDA polypeptides, widely found in the vegetable kingdom and implicated in cuticle formation and defense against pathogens (PR-14). They are thermostable and resistant to pepsin digestion, which makes them potent food allergens and explains the frequent development of systemic symptoms (urticaria, anaphylaxis) in patients allergic to Rosaceae fruits in Spain. LTPs have also been identified in other vegetable foods and in pollens and a marked degree of cross-reactivity among them has been demonstrated, which may explain (together with profilin) the frequency of individuals sensitized to vegetable foods in the Mediterranean area.     

Diagnostic usefulness of component-resolved diagnosis by skin prick tests and specific IgE to single allergen components in children with allergy to fruits and vegetables

IntroductionThe accurate identification of sensitizing proteins in patients allergic to plant-derived foods is extremely important, allowing a correct dietary advice. We aimed to evaluate the diagnostic usefulness of skin prick tests (SPT) and specific IgE (sIgE) with single molecular allergen components in children with allergy to fruits and vegetables.MethodsTwenty children underwent SPT with a palm profilin (Pho d 2, 50 μg/mL); a Mal d 1-enriched apple extract (2 μg/mL) (PR-10 allergen); and a peach Lipid Transfer Protein (LTP) (Pru p 3, 30 μg/mL). Detection of sIgE to rBet v 1, rBet v 2, Phl p 12 and Pru p 3 was also measured.ResultsAllergy to multiple fruits and vegetables was observed in 11 (55%) children. Sensitization by SPT to Pho d 2, Mal d 1, and Pru p 3 occurred in 5, 7, and 8 cases, respectively. LTP sensitization appeared to be associated with peach allergy but not with severe reactions, and profilins sensitization to melon and tomato allergy. Kiwi sensitization (12 cases), the plant-derived food that caused more allergic reactions, seemed mostly species-specific. The concordance of SPT extracts and sIgE to the corresponding pan-allergens was high for profilins (k = 0.857) and LTP (k = 0.706), while for PR-10 allergens it was absent (k = 0.079).ConclusionsPan-allergen sensitization in children with allergy to fruits and vegetables was common and often multiple. There was no association of severe reactions to LTP sensitization. The introduction of routine SPT to pan-allergens can be a simple and feasible way of improving diagnostic and therapeutic efficacy.     

Adult food allergy

Adult food allergy is estimated at approximately 3.2% worldwide. The persistence of childhood food allergy is unusual, peanut allergies excepted. Once established in adults, food allergy is rarely cured. Factors favoring the acquisition of allergy could be sensitization to pollens, occupational sensitization by inhalation, drugs (such as tacrolimus), and sudden dietary changes. Severe anaphylaxis and oral allergy syndrome are frequent. The fatality risk is estimated at 1% in severe anaphylaxis. Risk factors for severe anaphylaxis are agents causing increased intestinal permeability, such as alcohol and aspirin. β-blockers, angiotensin-converting enzyme (ACE) inhibitors, and exercise are other factors. Gastrointestinal food allergy remains, to a large extent, undiagnosed in adults. Food allergens are mainly fruit and vegetable, related to pollen sensitizations, or to latex allergy. Wheat flour allergy is increasing. The diagnosis relies on prick skin tests, detection of specific IgEs, and standardized oral challenges. Strict avoidance diets are necessary. Specific immunotherapy to pollens may be efficient for cross-reactive food allergies.     

Sensitivity and specificity of food specific IgE and IgG determinations for the diagnosis of food allergy

Among the methods currently used to demonstrate a sensitization to foods, the measurement of food specific IgE antibodies (sIgE) is the most practical but not the most accurate. The "sensitivity" of food sIgE determinations is, for example, suboptimal with unstable allergens in fruits and vegetables that are involved in the (birch) pollen-related immediate oral allergy syndromes. In this particular syndrome the history is often conclusive and can be substantiated by skin prick tests with fresh foods. The "sensitivity" of sIgE tests is much better when sIgE are directed to stable plant or animal food allergens which often cause non-immediate generalized reactions. Foods, usually, contain many different (glyco)proteinic allergens of which some are stable and others not. The "sensitivity" of the sIgE test with a particular food, therefore, varies according to the type of allergen that is recognized by the patient. The "specificity" of sIgE tests with foods is affected by the existence of homologous food allergens which induce cross-reactive IgE that may or may not be clinically relevant. While variable, clinical cross-reactivity is more common among botanically-related fruits, among different nuts, among mammalian foods and among seafood than among cereals, grains and legumes. The "specificity" of food sIgE tests is much better when sIgE are directed to unique non-cross-reactive food allergens. Unfortunately, neither the presence of food sIgE nor its level are predictive of clinical reactivity. The identification of individual allergens in foods and the characterization of the relevant IgE binding sites in these allergens might lead to the development of tests that only measure sIgE to clinical relevant food allergens.     

Study of food allergy in the Spanish population

BackgroundThe aim of the study was to investigate the prevalence of food allergy in patients referred to our Allergy Unit and to evaluate the diagnostic methods used.MethodsWe selected 674 patients referred to the Allergy Unit of our hospital from May 2002 to October 2004. The prevalence of symptoms was determined by a standardized questionnaire, prick-prick test, and serum specific IgE. In a second phase, double- blind oral challenge tests were administered.ResultsFood allergy was found in 106 patients (15.7%): 71 adults (67 %) and 35 children (33 %). The prevalence of food allergen sensitization was 14 % in adults and 20.8 % in children. A total of 89.6 % of the patients experienced symptoms immediately. Only 29.2% the patients of sought medical attention and adrenaline was administered to five (16.1 %). The foods most frequently involved in allergic reactions were fruits (56.6%) and tree nuts (22.6%).The most common symptoms were oral allergy syndrome (46.2 %), urticaria (32.1 %), and anaphylaxis (14.2 %).Combining the results of the questionnaire with those of prick-prick tests in patients whose allergy was confirmed by double-blind, placebo-controlled food challenge (9.1 %) showed a sensitivity of 95.5 %, a negative predictive value of 96 %, a specificity of 75 % and a positive predictive value of 73%.Conclusions1. The prevalence of food allergy in our sample was 9.1 %. 2. The foods most frequently involved in allergic reactions were fruits and tree nuts. 3. The most common symptoms were oral allergy syndrome, urticaria, and anaphylaxis. 4. Combining our questionnaire with in vivo tests allowed us to diagnose 75-96% of patients with no food allergy and 95 % of food allergy patients.     

What are the links between food allergy and atopy ?

Food allergy and atopy are closely linked. In children, food allergy is often the first clinical manifestation of atopy and involved in flares of atopic dermatitis. It is usually disappearing with ageing except for some particular allergens. Asthma and/or allergic rhinitis might develop later particularly if there are some risk factors as familial history of atopy or sensitization to aeroallergens. However some food allergies as allergy to peanut or tree nuts may persist in adulthood sometimes inducing severe clinical manifestations especially in asthmatic patients. In adult, food allergy is mostly associated with oral syndrome linked to cross reactivity between pollen and raw food (fruits or vegetables). Systemic manifestations are more frequent in patients living in the Mediterranean area in relation to direct sensitization (without pollen allergy) to lipid transfer proteins that are particularly resistant.     

Clinical and in vitro cross-reactivity of cereal grains in children with IgE-mediated wheat allergy

Introduction and ObjectivesWheat and cereal grains have a broad range of cross-reactivity, but the clinical relevance of this cross-reactivity is uncertain. This study aimed to evaluate clinical and in vitro cross-reactivity with barley, oat, and Job’s tears among wheat-allergic patients.Materials and MethodsPatients aged 5 to 15 years with IgE-mediated wheat allergy were enrolled. Skin prick test (SPT) and specific IgE (sIgE) to wheat, barley, and oat, and SPT to Job’s tears were performed. Oral food challenge (OFC) was conducted if the SPT was ≤5 mm in size and there was no history of anaphylaxis to each grain. Profiles of sIgE bound allergens of wheat, barley, and oat, and inhibition ELISA of IgE binding to barley and oat with wheat were performed.ResultsTen patients with a median age of 8 years were enrolled. Nine of those patients had a history of wheat anaphylaxis. The median SPT size and sIgE level to wheat was 7.3 mm and 146.5 kU_A/l, respectively. The cross-reactivity rate for barley, oat, and Job’s tears was 60.0%, 33.3%, and 20.0%, respectively. Significantly larger SPT size and higher sIgE level were observed in patients with positive cross-reactivity to barley and oat when compared to patients without cross-reactivity. Barley and oat extracts inhibited 59% and 16% of sIgE bound to wheat gliadins and glutenins, respectively.ConclusionThe cross-reactivity rate was quite low for oat and Job’s tears compared to that of barley; therefore, avoidance of all cereal grains may be unnecessary in patients with severe wheat allergy.     

Anaphylaxis following ingestion of mango fruit.

Allergic reactions to fresh fruits and nuts have become increasingly common. Mango (Mangifera indica) is a popular fruit eaten all over the world. We report the case of a 43-year-old woman who experienced oropharyngeal itching, swelling of the face and other parts of the body, and difficulty breathing within a few minutes of eating ripe mango fruit. The woman had no history of pollen or latex allergy. However, she reported instances of milder food allergic reactions to Indian dill and cashew apple. Skin prick tests using mango fruit pulp, Indian dill, and cashew apple extracts were positive. Prick tests with a panel of common grass and weed pollen extracts were negative. Enzyme-linked immunosorbent assay for mango-specific serum immunoglobulin (Ig) E was positive. A specific protein allergen in mango could not be detected by immunoblotting. Based on the strongly positive clinical history and results of allergy testing, it was concluded that the woman had IgE-mediated anaphylactic reactions to mango fruit.     

Allergies associated with both food and pollen

Recent progress in understanding structural relationships between allergens has allowed their classification into molecular families. Proteins belonging to a molecular family often show some degree of IgE cross-reactivity. These cross-reactions can lead to a clinical association like birch-apple syndrome whose basis is a sensitization to a PR-10 protein (birch pollen Bet v 1) and then oral symptoms in contact to apple Mal d 1, another PR-10 family member. Food allergens implicated into pollen-food allergy syndromes differ from those linked to crustacea or milk cross-allergies: they seem unable to sensitize the patient through oral route. As a result, they most often induce weaker clinical reactions than complete allergens like those present in shrimp or cow milk. Numerous molecular families have been isolated from pollens. PR-10 and profilins have a well established role in inducing clinical reactions to food like fruits and vegetables. Some molecular families need more studies to delineate their true impact on pollen-driven food reactions: polygalacturonases, pectate lyases, isoflavone reductases, thaumatin-like, cyclophilins.... Others are found in pollen but not in eaten products: 2-EF-hand calcium binding proteins, beta expansins,... Lipid transfer proteins (LTP) are widespread plant food allergens (e.g. in peach): these proteins seem able to directly sensitize the patient through oral route. But recent data have suggested a possible additional effect of some LTP present in pollens (mugwort, olive, pellitory).     

Frequency and clinical features of pollen-food syndrome in children

BackgroundPollen-food syndrome (PFS) is an allergic reaction to fresh fruits, vegetables and/or nuts that can occur in patients who are allergic to pollen. The prevalence of PFS in children is not clearly known.ObjectiveThe objective of this study was to determine the frequency and clinical features of PFS in pediatric patients with pollen-induced allergic rhinitis (AR).MethodThis study was conducted in the pediatric allergy outpatient clinic of our hospital. Pollen-induced seasonal AR patients who were evaluated for any symptoms appearing after consuming any fresh fruits and vegetables.ResultsSix hundred and seventy-two pollen-sensitized patients were included in this study. The symptoms related to PFS were reported in 22 (3.3%) patients. The median age of the patients was 12.3 years and 59% (n = 13) were female. Peach was the most common culprit (22%). There were isolated oropharyngeal symptoms in 20 (91%) patients and anaphylaxis in two (9%) patients with the suspected food. The multiple logistic regression analysis revealed that female gender, history of atopic dermatitis and allergic diseases in the family were the potential risk factors for PFS [Odds ratio 95%CI: 3.367 (1.344–8.435), 5.120 (1.935–13.550), 3.046 (1.239–7.492), respectively].ConclusionPFS can be seen in children who are followed up for pollen-induced AR. The symptoms of PFS are usually mild and transient. However, comprehensive evaluation of patients is important since serious systemic reactions such as anaphylaxis can also be observed.     

Component-resolved diagnostics can be useful for identifying hazelnut allergy in Japanese children

BackgroundCor a 9 and Cor a 14 are effective markers for predicting hazelnut allergy. However, there have been no reports on the component-resolved diagnostics (CRD) of hazelnut allergy using an oral food challenge (OFC) for diagnosis in Asia. We hypothesized that CRD would improve the accuracy of diagnosing hazelnut allergies in Japanese children.MethodsWe recruited 91 subjects (median age: 7.3 years) who were sensitized to hazelnuts and had performed a hazelnut OFC at the National Hospital Organization Sagamihara National Hospital between 2006 and 2017. All subjects were classified as allergic or asymptomatic to 3 g of hazelnuts. The sIgE levels (hazelnut/Cor a 1/Cor a 8/Cor a 9/Cor a 14/alder pollen) were measured using ImmunoCAP. We aimed to determine the predictive factors of hazelnut allergy.ResultsNine subjects (10%) were allergic to ≤3 g of hazelnuts. Levels of sIgE for Cor a 9 in hazelnut-allergic subjects were significantly higher than those in asymptomatic subjects (4.47 vs. 0.76 kU_A/L, p = 0.039). Levels of sIgE to alder pollen and Cor a 1 in hazelnut-allergic subjects were significantly lower than those in asymptomatic subjects (<0.10 vs 13.0 kU_A/L, p = 0.004; <0.10 vs 5.03 kU_A/L, p = 0.025). The area under the receiver operating characteristics curve for hazelnut/alder/Cor a 1/Cor a 9 was 0.55/0.78/0.72/0.71, respectively, with p = 0.651/0.006/0.029/0.040, respectively.ConclusionsThe findings of a high sIgE level for Cor a 9 and a low sIgE level for Cor a 1 can improve the diagnostic accuracy to better identify Japanese children sensitized to hazelnuts.     

Knowledge and attitudes of primary care physicians regarding food allergy and anaphylaxis in Turkey

BackgroundFood allergy, which becomes an important public health problem, can lead to important morbidity and mortality. Patients with food allergies are more likely to first present to their primary care physicians. We aimed to determine the knowledge of primary care physicians with regard to management of food allergies and anaphylaxis.MethodsPrimary care physicians were surveyed via a questionnaire aimed to document their knowledge and attitudes about food allergy and anaphylaxis management.ResultsA total of 297 participants completed questionnaires, 55.6% of which were female. Participating physicians had a mean of 17.0 ± 6.1 years of experience. Participants answered 47.2% of knowledge-based items correctly. Overall, participants fared poorly with regard to their knowledge on the treatment of food allergies and anaphylaxis. For example while 60.7% knew that a child can die from the milk allergy reaction, only 37.5% were aware that a child with IgE mediated milk allergies cannot eat yoghourts/cheese with milk. Besides, 53.1% of them chose epinephrine as their first treatment of choice in case of anaphylaxis, yet only 16.6% gave the correct answer about its dosage. Nearly a third of participants (36.7%) felt they were knowledgeable enough regarding the management of patients with food allergies, while 98.2% extended their request for future periodic educational meetings on allergic disorders.ConclusionKnowledge of food allergy and anaphylaxis among primary care physicians was unsatisfactory. Provision or periodic educational programmes should be aimed at improving the standard of practice as acknowledged by the participants.     

Food anaphylaxis in antiphospholipid syndrome and thrombosis

BackgroundWe have observed that some cases of food anaphylaxis were followed by severe thrombosis associated to anticardiolipin antibodies. Food anaphylaxis associated with antiphospholipid syndrome has seldom been published.ObjectiveThe aims were: 1) to test anticardiolipin antibodies in an important number of patients with anaphylaxis due to vegetal foods and their relationship with possible thrombosis; and 2) to study seed and fruit hypersensitivity in patients with previous thrombotic events associated with antiphospholipid antibodies (aCL).MethodsWe included 30 patients diagnosed of thrombosis associated with aCL, 52 patients who suffered from anaphylaxis due to seeds or fruits, and 120 control patients. Haematological, cardiopulmonary vascular and rheumatologic studies had been performed as needed. In vivo and in vitro allergy tests with a large battery of vegetal allergens were carried out in all the patients. Measurement of IgG aCL antibodies and specific IgE to vegetal food was done by ELISA and CAP-FEIA (Phadia). Immunodetection and inhibitions with lipoproteins belonging to seeds were performed.ResultsSeventy-five percent of the patients diagnosed as having antiphospholipid primary syndrome had specific IgE against different proteins from different vegetable allergens, most of them seeds, and clearly against lipoproteins that were also recognised by the patients with food anaphylaxis but not by the control cases. Among the patients with anaphylaxis, 28% had anticardiolipin antibodies and 17.3% thrombosis.ConclusionOur study suggests that seed lipoproteins which cause severe food anaphylaxis might have a potential role in the antiphospholipid syndrome and related thrombosis.     

Food allergy in Catalonia: Clinical manifestations and its association with airborne allergens

BackgroundFood allergy affects around 6% of the European population and its prevalence worldwide has been increasing in the last decades, but studies focused on investigating food allergy epidemiology in Europe are lacking.ObjectiveThe Cibus project was created to register the main culprit foods and their clinical manifestations in food allergic patients in Catalonia.MethodsA specific online database was designed. Allergists from eight different Catalan hospitals registered the new diagnoses of food allergy.Results618 food allergic patients were included. Egg and milk were the main elicitors in the early ages, while fruits and nuts were the most frequent in patients >14 years old. Fish was more frequent in children, while seafood and Anisakis allergy were more frequent in the >14-year-old group. Overall, peach was the most prevalent food eliciting an allergic reaction (10%). Food allergy diagnosis was reached using compatible clinical history and positive skin prick test to the involved food in 98% of cases. Globally, urticaria was the most frequently reported manifestation in our population (48.2%), followed by oral allergy syndrome (25.6%) and anaphylaxis (24.8%).ConclusionsThe Cibus project gives a full overview of the profile of food allergic patients in Catalonia and reinforces the predominance of plant food allergies in the Mediterranean area.     

The Role of Lipid Transfer Proteins in Allergic Diseases

Nonspecific lipid transfer proteins (LTPs) are important allergens in fruits, vegetables, nuts, pollen, and latex. Despite their wide distribution throughout the plant kingdom, their clinical relevance is largely confined to the Mediterranean area. As they can sensitize via the gastrointestinal tract, LPTs are considered true food allergens, and IgE reactivity to LTPs is often associated with severe systemic symptoms. Although Pru p 3 represents the predominant LTP in terms of patients’ IgE recognition, the contribution of pollen LTPs in primary sensitization cannot be ruled out. Due to structural homology, LTPs from different allergen sources are generally IgE cross-reactive. However, sensitization profiles among allergic patients are extremely heterogeneous, and individual cross-reactivity patterns can be restricted to a single LTP or encompass many different LTPs. Molecule-based approaches in allergy research and diagnosis are important for better understanding of LTP allergy and could assist clinicians with providing adequate patient-tailored advice.     

Food allergy in adolescents and adults

There has been an increase in the prevalence of food allergy in the last few decades. Adult food allergy may represent persistence of reactions that commenced in infancy and early childhood or it may be initiated in adulthood through new sensitizations. Persistence of peanut allergy is an example of the former situation. Approximately 20% of children will develop tolerance to peanuts, so there will be an increasing number of individuals reaching adulthood where this problem will need ongoing management. In addition to peanut, tree nuts, fruits, vegetables and seafood are implicated as common causes of food allergy in adulthood. Sensitization may occur directly to a food allergen or indirectly through cross-reactivity with an aeroallergen. Adults may present with a spectrum of clinical manifestations from oral allergy syndrome to fatal anaphylaxis. The management of food allergy consists of appropriate education regarding avoidance of implicated foods, modifying potential risk factors for anaphylaxis, such as asthma and prompt recognition and treatment of acute reactions.     

IgE reactivity to profilin in Platanus acerifolia pollen-sensitized subjects with plant-derived food allergy.

BACKGROUND: The presence of profilin-specific IgE antibodies is a cause of cross-reactivity between botanically-unrelated allergen sources. Recently, the association between Platanus acerifolia pollinosis and plant-derived food allergy has been described. The aim of this study was to ascertain whether the P. acerifolia profilin is involved in such cross-reactivity. METHODS: Twenty-three patients suffering from Platanus acerifolia pollinosis and plant-derived food allergy were evaluated in an allergy department. Specific IgE levels to P. acerifolia pollen, P. acerifolia profilin and food extracts were measured. Molecular masses of IgE-binding proteins were calculated by Western blotting and cross-reactivity studies among P. acerifolia profilin and different food extracts were evaluated by Enzyme AllergoSorbent Test (EAST)-inhibition assays. Also, EAST-inhibition assays with the two known P. acerifolia allergens, Pla a 1 and Pla a 2, were performed. RESULTS: Surprisingly, a high IgE-binding prevalence (90%) of P. acerifolia profilin was found. EAST-inhibition showed high inhibition values when Platanus acerifolia pollen extract was used as free phase and plant-derived food extracts as solid phase, whereas the other way round showed low inhibition values. IgE reactivity to profilin was studied using a pool of patient sera, by EAST-inhibition assays with hazelnut, apple peel, peanut, chickpea and peanut extracts as solid phase and no inhibition was obtained when P. acerifolia profilin was used as inhibitor phase. The same results were obtained when purified Pla a 1 and Pla a 2 were also used as inhibitor phase. CONCLUSIONS: The clinical association observed between Platanus acerifolia pollen and plant-derived food could be explained by the in vitro IgE cross-reactivity detected by EAST-inhibition. However, it appears that neither P. acerifolia profilin nor the two major allergens described (Pla a 1 and Pla a 2) can explain such a strong cross-reactivity.     

Diagnosing Pollen-food Allergy Syndrome Allergologically in a Patient with Suspected Eosinophilic Gastroenteritis

Pollen-food allergy syndrome (PFAS) consists of type I allergy to pollen and multiple food items that are cross-reactive to the pollen. PFAS typically occurs in the oral cavity and can co-occur with eosinophilic esophagitis. However, it is infrequently reported to present with symptoms of eosinophilic gastroenteritis (EGE), such as abdominal pain and eosinophilic infiltration of the gastrointestinal tract. We herein report a patient with a condition initially suspected of being EGE based on symptoms and pathological findings that was later diagnosed as PFAS associated with birch pollen. PFAS should be considered as a differential diagnosis in patients with EGE-like symptoms.     

Prevalence of oral allergy syndrome in children with allergic diseases

IntroductionThe oral allergy syndrome (OAS) is a particular type of food allergy rarely explored in the paediatric population that is already considered an adult problem.ObjectiveIdentify the prevalence of OAS, symptoms and pollen species associated with its presence in children affected by allergic diseases.MethodsA cross-sectional study was conducted. Consecutive sampling included children from 6 to 14 years who needed allergy treatment for the first time. A structured questionnaire was carried out to collect demographic and clinical data and history of OAS. Besides sensitisation to various allergens, the skin prick-by-prick test was performed to corroborate sensitisation to food related to OAS. Prevalence of OAS and its association with pollens was established following the covariate adjusted logistic regression.Results267 subjects were included. Overall prevalence of OAS was 8.9% (95%CI 6.1–13.1%). Prevalence of OAS for allergic rhinitis and asthma were 8.8% and 9.1%, respectively. In patients sensitised to pollen, the prevalence ranged from 9.6% to 12.2% depending on the type of pollen. 62.5% of children with OAS were sensitive to pineapple. After adjusting for gender and family history of atopic disease, trees from the Quercus species showed an association with OAS (OR = 2.7, 95%CI 1.2–6.2).ConclusionsOAS is not uncommon in our environment. Pineapple, a typical fruit from the region, was the main food related. Quercus sp., but not birch nor olive, was the pollen associated with this syndrome.