Allergy to cooked white potatoes in infants and young children: A cause of severe,chronic allergic disease

BACKGROUND: Cases of allergy to cooked potato in children have been reported, some with immediate and others with late reactions. The clinical effects of chronic allergic reactions to potato and the effectiveness of diet on such reactions have not been described previously. OBJECTIVE: We sought to evaluate the importance of cooked potato as an allergenic food in individual cases of atopy in children. METHODS: Eight atopic children were selected on the basis of suspicion of allergy to cooked potatoes: all had potato-specific IgE, 2 of 8 had experienced immediate allergic reactions, and 6 of 8 had eczema that improved with a potato-elimination diet (decrease in severity scoring of atopic dermatis [SCORAD] index of >50%). The patients were evaluated by using skin prick tests with homemade cooked and noncooked potato extracts and with a commercial extract and by using IgE immunoblots from SDS-PAGE patterns of potato extract. Seven patients were challenged with cooked potato. The control group consisted of 9 age-matched atopic children, 8 of them with eczema. RESULTS: The mean SCORAD index decreased from 43.3 before to 11.5 after elimination of potato from the diet. Potato CAP values ranged from 3.71 to greater than 100 kUa/L. Potato challenge results were positive in 7 of 7 patients. Skin prick test responses were positive for cooked potato extracts in 7 of 7 patients, for noncooked extracts in 7 of 7 patients, and for the commercial extract in 8 of 8 patients compared with in 0 of 9, 1 of 9, and 1 of 9 subjects in the control group, respectively. During immunoblotting, 8 of 8 patient sera recognized one or more protein bands compared with 0 of 9 control subject sera. CONCLUSION: Allergy to cooked potatoes is a cause of severe allergic disease, with immediate reactions and eczema in some atopic infants and young children.     

Lupin allergy in peanut-allergic children and teenagers

Background:  Lupin has now been introduced into food production in the UK. There is a concern that, on account of cross-reactivity, peanut-allergic children are at high risk for lupin allergy.
Aims:  To investigate the prevalence of lupin sensitization and allergy in children with peanut allergy compared with atopic controls.
Methods:  Children (<18 years) were recruited. Peanut-allergic subjects either had a convincing history of peanut allergy with diagnostic peanut skin prick test (SPT) or specific-immunoglobulin E (IgE) results or a positive food challenge. Control subjects were atopic but not peanut-allergic. All subjects had SPT to peanut and lupin. Sensitized subjects were offered a randomized, double-blind, placebo-controlled lupin challenge. Lupin allergy was defined as objective immediate hypersensitivity reaction at food challenge.
Results:  Forty-seven peanut-allergic children and 46 atopic controls were recruited. Sixteen peanut-allergic children were sensitized to lupin [34%, 95% confidence interval (CI): 21–49%]. Nine were challenged to lupin. Two reacted (itchy mouth and urticaria; itchy mouth and 20% drop in peak expiratory flow rate) giving a minimum prevalence of lupin allergy in peanut-allergic children of 4.0% (95% CI: 1–15%). Atopic controls were significantly ( P  = 0.001) less likely to be sensitized to lupin (4%, 95% CI: 1–15%) and had smaller wheals and serum-specific IgE results. None of the atopic controls reacted on lupin challenge, giving a rate of allergy in the atopic controls of 0% (95% CI: 0–8%).
Conclusions:  A small but significant number of children with peanut allergy are allergic to lupin. Sensitization to lupin is much rarer in nonpeanut-allergic atopic subjects.     

The diagnosis of Brazil nut allergy using history, skin prick tests, serum-specific immunoglobulin E and food challenges

BACKGROUND: Allergy to Brazil nut is a relatively common nut allergy and can be fatal. However, the evidence is lacking regarding the best approach to its diagnosis. OBJECTIVE: We sought to determine the relative merits of history, skin prick testing, measurement of serum-specific IgE and challenge in the diagnosis of Brazil nut allergy. METHODS: Fifty-six children and adults with a history of an allergic reaction to Brazil nut or evidence of sensitization were investigated by questionnaire (n=56), skin prick tests (SPTs) (n=53), measurement of serum-specific IgE to Brazil nut (n=54) and double-blind, placebo-controlled labial, and if necessary oral, challenges (n=19). RESULTS: Brazil nut allergy occurred in highly atopic individuals of any age with a strong family history of atopy. In 24 of 56 (43%), the history of an immediate reaction was sufficient to make a diagnosis with confidence and an oral challenge was considered unsafe. Of the 19 subjects undertaking the 'gold standard' test of a double-blind, placebo-controlled, food challenge, all six subjects with a SPT of at least 6 mm had a positive challenge and all three subjects with a SPT of 0 mm had a negative challenge. In the remaining 10 (53%) subjects, where SPT was between 1 and 5 mm and serum-specific IgE was less than 3.5 kU/L, an oral challenge was performed resulting in three positive and seven negative challenges. CONCLUSION: A combination of history, SPT and serum-specific IgE was adequate in achieving a diagnosis in the majority (77%) patients with suspected Brazil nut allergy. However, a doubtful history with SPT between 1 and 5 mm, or a serum-specific IgE less than 3.5 kU/L may require an oral challenge to help determine the risk of a Brazil nut allergic reaction.     

Allergy to Apple, Carrot and Potato in Children with Birch Pollen Allergy

Skin sensitivity to apple, carrot and potato, clinically related to birch pollinosis was investigated. Different skin test techniques using fresh fruit were compared. A simple prick test (SPI) technique with a lancet piercing the apple peel just before pricking the skin was shown to be the most practical and to give reproducible results. The allergenic activity in apple was found to be heat labile and deteriorated during storage at room temperature, Apple, carrot, potato, hazelnut and birch reactivity was transferable in Prausnitz-Küstner test like IgE antibodies. SPT reactivity to fresh material from apple, carrot and potato was investigated in 174 children of whom 128 suffered from pollen allergy. Positive SPT results were obtained almost exclusively in children who were SPT positive to a birch pollen extract. Children who noticed clinical symptoms when eating apple, raw carrot or potato were found to have a significantly larger SPT reaction than children with a negative history.     

Brassica oleracea pollen, a new source of occupational allergens

BACKGROUND: Vegetable pollen is a rare source of occupational allergens. Occupational allergy has only been described in the case of paprika pollen and tomato pollen. We describe a new source of occupational pollen allergy. AIM: To study the incidence and the impact of broccoli and cauliflower pollen allergy in employees involved in classical plant breeding. METHODS: Fifty-four employees of five companies working with cauliflower (Brassica oleracea botrytis) and broccoli (B. oleracea italica/cymosa) pollen were eligible for complete evaluation. Allergy to cauliflower and broccoli pollen was evaluated by questionnaire and determination of sensitization by radioallergosorbent test (RAST) and skin-prick tests (SPT). SPT and RAST were performed with a panel of commercial and homemade extracts from cauliflower and broccoli pollen. RESULTS: Work-related symptoms such as rhinitis, conjunctivitis, asthma and urticaria caused by B. oleracea pollen were reported by 44% of the participants (24/54), of whom all but one had positive SPT for cauliflower- and/or broccoli-pollen/flower extracts and 58% (14/24) had positive RAST results. Symptoms had developed within the first 2 years in 33% of the patients. Six patients had to stop or change work. CONCLUSIONS: Brassica oleracea pollen is a new source of occupational allergen with strong allergenic potential leading to symptoms in almost half of the exposed employees.     

A cross‐sectional study on the prevalence of food allergy to eggplant (Solanum melongena L.) reveals female predominance

Background Only a few case reports of allergy to eggplant (Solanum melongena) have been reported. A relatively large number of individuals appear to experience food‐related symptoms to eggplant in India. Objective The major aims of this study are to assess the prevalence of food allergy to eggplant and analyse the age and gender distribution. Methods Seven hundred and forty‐one subjects (age range: 5–60 years) randomly selected from rural and urban areas of Mysore city were analysed for the prevalence of eggplant allergy based on case history, skin prick test (SPT) with eggplant extracts and allergen‐specific IgE. The age and gender distribution for the prevalence of eggplant allergy and its association with other atopic conditions were assessed. Results Sixty‐eight (9.2%) subjects reported adverse reactions to ingestion of eggplant, of which 32 (4.3%) subjects had positive history/positive SPT and 36 (4.9%) had positive history/negative SPT. Sixteen (2.2%) subjects had negative history/positive SPT. Ten subjects (1.4%) experienced allergic symptoms in <2 h. Sensitization to eggplant by SPT was more in atopic (16.7%) compared with non‐atopic subjects (3.8%). All the SPT‐positive subjects (n=48) underwent evaluation for eggplant allergen‐specific IgE, which was detected in 6 subjects (0.8%). Majority of the subjects sensitized to eggplant were in the age groups 16–45 years, and females were twice as likely to be sensitized as males. Female predominance (4 : 1) is more in the 16–30 year group. Conclusions Many subjects experience adverse reactions to the ingestion of eggplant, possibly due to the pharmacologic action of histamine and other non‐protein components, rather than to specific protein allergen(s). The prevalence of IgE‐mediated eggplant allergy is estimated at ～0.8%, with higher rates of sensitization in females.     

Long-term repeatability of the skin prick test is high when supported by history or allergen-sensitivity tests: a prospective clinical study

BACKGROUND: Long-term reproducibility of the skin-prick test (SPT) has been questioned. The aim of the study was to investigate the clinical relevance of SPT changes. METHODS: SPT to 10 common inhalation allergens was performed annually from 1999 to 2001 in 25 nonsensitized and 21 sensitized subjects. An SPT was positive when > or =3 mm, and repeatable if either persistently positive or negative. Clinical sensitivity to birch pollen was used as model for inhalation allergy, and was investigated at inclusion and at study termination by challenge tests, intradermal test, titrated SPT and IgE measurements. Birch pollen symptoms were confirmed in diaries. RESULTS: The repeatability of a positive SPT was 67%, increasing significantly to 100% when supported by the history. When not supported by history, the presence of specific IgE was significantly associated with a repeatable SPT. Allergen sensitivity was significantly lower in subjects loosing SPT positivity. The repeatability of a negative test was 95%, decreasing significantly to 87% by the presence of other sensitization. Development of a positive SPT was clinically relevant. Elevation of SPT cut-off point did not enhance repeatability. CONCLUSION: SPT changes are clinically relevant. Further studies using other allergens are needed. Long-term repeatability of SPT is high in the presence of a supportive history.     

Mustard allergy in children

BACKGROUND: Mustard allergy is not well known. This study aimed to assess its clinical features and other associated allergies, and to define skin prick tests (SPT), specific IgE, and dose response by oral food challenge. METHODS: Our study investigated 36 children with positive mustard SPT. The diagnosis of mustard allergy was based on open or single-blind, placebo-controlled food challenge (SBPCFC). We compared the subjects to 22 controls. RESULTS: The initial clinical features were atopic dermatitis (51.8%), and urticaria and/or angioedema (37%). Fifteen children were allergic (positive SBPCFC) and 21 children were nonallergic (negative SBPCFC). Symptoms after mustard ingestion started under 3 years of age in 53.3% of the subjects. There was no significant difference in the food allergies and associated inhalant allergen sensitizations between the two groups. In the allergic group, the mean wheal diameter for mustard SPT was 8.8 mm and the median concentration of mustard serum (s) IgE 14.8 kU/l. The mean cumulative reactive dose were 153 mg. CONCLUSIONS: Allergic reactions to mustard started early in life. Clinical symptoms were not severe in children. Mustard should be included in screening tests of food allergy in children.     

Allergy to white potato

Allergy to potato is uncommon, and even more uncommon is allergy to potato pollen. The occurrence of both phenomena in the same patient made it possible to study cross-reactivity patterns of potato antigens. An 11-year-old girl, exclusively breast-fed for her first 4 months, developed anaphylactic symptoms after ingestion of potato at 5 months of age when she was fed potato for the first time. Subsequently, she developed urticaria, angioedema, and respiratory and systemic symptoms on contact with potatoes, ingestion of potatoes, and exposure to cooking potatoes or potato pollen. Three allergenic extracts from potato pulp, peel, and pollen were prepared. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and isoelectrofocusing of the three extracts were performed. IgE-mediated allergy to these extracts was demonstrated by means of immediate skin test reactivity, positive passive transfer, RAST, RAST inhibition, and leukocyte histamine release. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the pulp extract followed by electroblotting and autoradiography demonstrated specific IgE antibodies directed against several proteins ranging from 14,000 to 40,000 daltons.     

Allergy to jackfruit: a novel example of Bet v 1-related food allergy

BACKGROUND: Jackfruit allergy has been reported just once. It is unknown whether this food allergy is caused by direct sensitization or cross-sensitization to pollen allergens. OBJECTIVE: Establish whether jackfruit allergy is linked to birchpollen allergy. METHODS: Two jackfruit allergic patients and five patients with birchpollen-related apple allergy were recruited. Sensitization to pollen and plant foods was assessed by skin prick test (SPT), radio-allergosorbent test (RAST) and immunoblot. RAST analysis was performed for Bet v 1 and Mal d 1. Cross-reactivity was evaluated by RAST and immunoblot-inhibition. Biological activity of immunoglobulin E (IgE) was measured by basophil histamine release. Allergy to jackfruit was evaluated by double-blind placebo-controlled food challenge (DBPCFC) or open challenge (OC). RESULTS: In both patients DBPCFC confirmed the reported jackfruit allergy. SPT was 41 and 27 mm2 and specific IgE to jackfruit was 5.9 and 0.8 IU/ml, respectively. Immunoblot analysis revealed IgE reactivity at Mr of approximately 17 kDa. The Bet v 1-related nature of this allergen in jackfruit was demonstrated by RAST and immunoblot inhibition. To assess whether jackfruit allergy might be common in patients with combined birchpollen-fruit allergy, five such patients underwent an OC with jackfruit. All five had OA-like symptoms. CONCLUSIONS: Jackfruit allergy can be added to the list of birchpollen-related food allergies. Increased consumption of this fruit will result in a rise in allergic reactions.     

How long does the effect of birch pollen injection SIT on apple allergy last?

Background: Recent studies showed that injection specific immunotherapy (SIT) with birch pollen extract greatly reduces or cures the associated apple allergy in a large proportion of birch pollen-allergic patients. However, the long-term efficacy of SIT for apple allergy has not been assessed. Objective: To evaluate the duration of the effect of injection SIT with birch pollen extract on apple allergy in birch pollen-allergic patients. Methods: Thirty birch pollen-allergic patients showing both the clinical disappearance of apple allergy and a negative SPT with fresh apple at the end of their injection SIT course were followed-up at 12-month intervals from 6 months after SIT was stopped. Apple tolerance as well as SPT was assessed on all occasions. Fifty-seven birch pollen-allergic subjects without apple allergy and not submitted to SIT regularly followed-up for the onset of oral allergy syndrome (OAS) were used as controls. Results: The overall prevalence of OAS after 30 months of follow-up did not differ between patients and controls. Although most patients became re-sensitized to apple by SPT over time, >50% of them were still able to tolerate eating the fruit at the 30-month follow-up visit. Conclusion: Although most patients show a ‘natural’, gradual propensity to apple re-sensitization (a consequence of prolonged and repeated inhalation of birch pollen responsible for primary sensitization?), the clinical effects of injection SIT on food allergy seem rather long lasting.     

Skin prick test can identify eczematous infants at risk of asthma and allergic rhinitis

BACKGROUND: Assessment of allergic sensitization is not routinely performed in infants and young children with eczema. OBJECTIVE: To determine whether infants who have atopic eczema (with sensitization) are at a greater risk of developing asthma and allergic rhinitis (AR) than those with non-atopic eczema (without concurrent sensitization). METHODS: The presence of eczema was prospectively documented until 2 years of age in a birth cohort of 620 infants with a family history of atopic disease. Sensitization status was determined by skin prick tests (SPTs) at 6, 12, and 24 months using six common allergens. Interviews were conducted at 6 and 7 years to determine the presence of asthma and AR. RESULTS: Within the first 2 years of life, 28.7% of the 443 children who could be classified had atopic eczema: 20.5% had non-atopic eczema, 19.0% were asymptomatic but sensitized and 31.8% were asymptomatic and not sensitized. When compared with children with non-atopic eczema in the first 2 years of life, children with atopic eczema had a substantially greater risk of asthma [odds ratio (OR)=3.52, 95% confidence interval=1.88-6.59] and AR (OR=2.91, 1.48-5.71). The increased risk of asthma was even greater if the infant had a large SPT (OR=4.61, 2.34-9.09) indicative of food allergy. There was no strong evidence that children with non-atopic eczema had an increased risk of asthma or AR compared with asymptomatic children. CONCLUSION: In children with eczema within the first 2 years of life, SPT can provide valuable information on the risk of childhood asthma and AR.     

Concurrent cereal allergy in children with cow''s milk allergy manifested with atopic dermatitis

BACKGROUND: There is increasing consensus about the significance of food allergens in the pathogenesis of atopic dermatitis (AD) in infancy and childhood, with cow's milk and egg accounting for most of the reactions. Previous studies have indicated that multiple food sensitization, such as cereals, is very common in patients with cow's milk allergy (CMA). Evidence is lacking, however, as to its clinical relevance. OBJECTIVE: The purpose of this study was to determine the concurrent occurrence of cereal allergy among children with challenge-proven CMA who have residual symptoms, such as AD and/or gastrointestinal symptoms, during cow's milk elimination diet. Further, we sought to evaluate the utility of patch testing in prescreening foods other than cow's milk behind allergic symptoms in children. METHODS: The study population comprised 90 children, aged from 2.5 to 36 months (mean 1.1 years), with challenge-proven CMA. As a result of residual symptoms during meticulous cow's milk elimination diet (AD: n=80, and gastrointestinal: n=10), the children were put on a cereal elimination diet (oats, wheat, rye, and barley) and skin prick tests (SPT) and patch testing with cereals were performed. Open cereal challenge was performed to confirm cereal allergy. RESULTS: Cereal challenge was positive in 66 (73%) of the children with CMA. Of them, 17% reacted with immediate reactions and delayed-onset reactions were seen in 83% of the children. SPT was positive in 23%, patch test in 67%, and either SPT or patch test was positive in 73% of the children with cereal allergy. SPT gave the best positive predictive value, whereas SPT together with patch test gave the best negative predictive value. CONCLUSIONS: Residual symptoms, such as eczema or gastrointestinal symptoms in CMA children may be a sign of undetected allergy to other food antigens. SPT with cereals aids in diagnosing cereal allergy in small children, especially when used together with patch testing.     

Latex allergy and latex sensitization in children and adolescents with meningomyelocele

Background: The high prevalence of clinical latex allergy and latex sensitization in children with meningomyelocele has been widely reported. It has also been noted that these same children have a higher than expected prevalence of atopic disease. It would be useful to have a safe, sensitive, and specific skin test to detect latex sensitivity and to know how well this test compares with available in vitro tests. It would likewise be helpful to know as fully as possible the characteristics of the individual and to evaluate the relative importance of factors suspected to contribute to clinical latex allergy and latex sensitization in this population. Methods: A group of 116 children and adolescents 1 to 20 years of age were recruited for the study. An extensive history of latex allergy, atopic diseases, and surgical procedures was taken on all subjects. Each subject had either a latex skin test or an in vitro study for latex-specific IgE, and 67 subjects had both tests simultaneously. Eighty-five subjects had epicutaneous skin tests to a panel of environmental allergens. Results: Overall, 25 of 116 (21.5%) subjects had a history of clinical latex allergy, and 51 of 116 (44%) were sensitized to latex. The sensitivity and specificity of skin tests for clinical latex allergy were slightly greater than for the in vitro test (100% vs 95.8% and 82.3% vs 68.9%, respectively). The positive predictive value and negative predictive value of skin testing for clinical latex allergy were also greater (67.6% vs 50% and 100% vs 98.1%, respectively). Age was found to be a significant variable for both latex allergy and latex sensitization. The number of surgical procedures undergone and the presence of positive skin test responses to environmental allergens were significantly correlated with latex sensitization but not with clinical allergy to latex. Conclusions: A sensitive, specific, and safe skin test for latex sensitivity appears superior to in vitro testing for latex allergy. Age, number of surgical procedures, and the presence of positive allergen skin test responses are significantly correlated with latex sensitization. Age alone is significantly correlated with clinical allergy to latex. (J Allergy Clin Immunol 1998;101:741-6.)     

Housewives with raw potato-induced bronchial asthma

Allergy to white potato has rarely been described. We report two cases of atopic patients, housewives, in whom peeling raw potatoes precipitated rhinoconjunctivitis and asthmatic attacks, and, in one of them, contact urticaria. Type I hypersensitivity to raw potato antigens was demonstrated by means of immediate skin test reactivity, specific IgE determination by RAST, basophil degranulation, histamine release test and an immediate bronchial provocation test response to raw potato extract. The controls did not react to any of these tests. Potato allergenic constituent is currently being investigated but, as far as we know, it is heat-labile and has an MW of more than 10 Kd.     

A longitudinal study of resolution of allergy to well‐cooked and uncooked egg

Background Egg allergy is common and although resolution to uncooked egg has been demonstrated, there is lack of evidence to guide reintroduction of well‐cooked egg. Objectives To examine the rate of resolution to well‐cooked, compared with uncooked egg in children, and safety of egg challenges. Method A longitudinal study of egg‐allergic children from 2004 to 2010, who underwent challenge with well‐cooked and if negative, uncooked egg. Participants underwent repeat annual challenges and egg‐specific IgE measurement. Results One hundred and eighty‐one open egg challenges were performed in 95 children whose median age of allergy onset was 12 months. Fifty‐three of 95 (56%) had at least one annual repeat challenge. Pre‐study historical reactions occurred to baked egg in five (5%), lightly cooked in 58 (61%) and uncooked in nine (9%); respiratory reactions occurred in 11 (12%) and seven (7%) had anaphylaxis; adrenaline was used during five reactions. There were 77 well‐cooked and 104 uncooked egg challenges. Tolerance was gained twice as rapidly to well‐cooked than uncooked egg (median 5.6 vs. 10.3 years; P<0.0001) and continued to 13 years; hazard ratio 2.23 (95% confidence interval 1.6–3.9). Nearly 1/3 had resolved allergy to well‐cooked egg at 3 years and 2/3 at 6 years. Of 28/77 (37%) positive well‐cooked egg challenges, 65% had cutaneous symptoms, 68% gastrointestinal and 39% rhinitis, with no other respiratory reactions. Adrenaline was not required. Conclusions and Clinical Relevance Resolution of egg allergy takes place over many years, with children outgrowing allergy to well‐cooked egg approximately twice as quickly as they outgrow allergy to uncooked egg. There were no severe reactions to well‐cooked egg challenge, and adrenaline was not required. Our data support initiation of home reintroduction of well‐cooked egg from 2 to 3 years of age in children with previous mild reactions and no asthma. Resolution continues to occur in older children, so that despite an earlier positive challenge, attempts at reintroduction should be continued. Cite this as: A. Clark, S. Islam, Y. King, J. Deighton, S. Szun, K. Anagnostou and P. Ewan, Clinical & Experimental Allergy, 2011 (41) 706–712.     

Combined skin prick and patch testing enhances identification of peanut-allergic patients with atopic dermatitis

BACKGROUND: Food atopy patch tests (APTs) are considered a useful tool for the diagnosis of food allergy. Hypersensitivity to peanuts has not been investigated by means of APTs so far. METHODS: APTs and skin prick tests (SPTs) with peanuts were performed in 136 atopic dermatitis (AD) patients. Relevance of positive and negative responses to these tests was assessed by repeated open challenges with peanuts. RESULTS: Nine percent of our AD patients reacted to the challenge. Positive responses to APTs were recorded in 19% of the patients, whereas in 12% positive SPTs were observed. APTs were more frequently positive in subjects with eczematous responses after challenge with respect to those with urticarial reactions. SPT reactivity proved to be higher in patients above 12 years of age, whereas APT positivity was more frequent in children under 6 years. APT sensitivity proved significantly higher than SPT sensitivity, in particular in children under 12 years of age. On the contrary, SPT specificity and positive predictive value were significantly higher with respect to those of APT in the age group of subjects under 6 years of age. CONCLUSIONS: Our data suggest that APTs with peanuts may represent a useful integration to standard testing modalities employed for the diagnosis of peanut allergy in AD patients.     

Hunt for the origin of allergy – comparing the Finnish and Russian Karelia

The Finnish and Russian Karelia are adjacent areas in northern Europe, socio‐economically distinct but geoclimatically similar. The Karelia Allergy Study was commenced in 1998 to characterize the allergy profiles in the two areas. Allergy prevalence had increased in Finland since the early 1960s, but the situation in Russia was unknown. The key finding was that allergic symptoms and diseases were systematically more common in Finnish children and adults than in their Russian counterparts. For example, in the early 2000s, hay fever in school children was almost non‐existent in Russian Karelia, and only 2% were sensitized to birch pollen compared with 27% in Finnish Karelia. Adult birth cohorts showed that among those born in the 1940s, the sensitization to pollens and pets was at the same low level in both countries, but among younger generation born in the late 1970s, the difference was already manifold. Seropositivity to some pathogens, microbial content in house dust and drinking water seemed to confer allergy protection in Russia. In subsequent studies, it became apparent that on the Finnish side, healthy children had a more biodiverse living environment as well as greater diversity of certain bacterial classes on their skin than atopic children. Abundance of skin commensals, especially Acinetobacter (gammaproteobacteria), associated with anti‐inflammatory gene expression in blood leucocytes. In vivo experiments with the mouse model demonstrated that intradermally applied Acinetobacter protected against atopic sensitization and lung inflammation. These observations support the notion that the epidemic of allergy and asthma results from reduced exposure to natural environments with rich microbiota, changed diet and sedentary lifestyle. Genetic studies have confirmed strong influence of lifestyle and environment. With our results from the Karelia study, a 10‐year National Allergy Programme was started in 2008 to combat the epidemic in Finland.     

Profilin sensitization detected in the office by skin prick test: a study of prevalence and clinical relevance of profilin as a plant food allergen

Background Profilin, a pan‐allergen present in all eukaryotic cells, is one of the main causes of cross‐sensitization between pollen and plant‐derived foods, but its clinical relevance as a food allergen is still debated. Objective To investigate the prevalence of profilin sensitization in a pollen‐allergic population and its clinical relevance as a food allergen. Methods Two hundred consecutive patients with pollen allergy underwent skin prick tests (SPT) with purified natural date palm profilin (Pho d 2; 50 μg/mL; Alk Abello, Madrid, Spain). Those reporting adverse reactions to foods (confirmed by SPT with either commercial food extracts or fresh foods) underwent SPT with an apple extract containing uniquely Mal d 1 (2 μg/mL; ALK‐Abello), and with a commercial peach extract containing uniquely lipid transfer protein (LTP 30 μg/mL; ALK‐Abello). Results Sixty patients (30%) showed skin reactivity to date palm profilin, Pho d 2. All were sensitized to grass pollen, and most of them reacted to birch, mugwort, ragweed and plantain pollen as well. SPT with pellitory and cypress scored negative in a high proportion of profilin reactors [26/60 (43%) and 33/60 (55%), respectively]. More than one half (34/60 [57%]) of profilin reactors had food allergy; 21 of these were monosensitized to profilin, 11 were sensitized to both profilin and Bet v 1 homologous protein, one to both profilin and LTP, and one to all the three allergens. The large majority of profilin‐allergic patients reported oral allergy syndrome as the only food‐induced symptom and were able to tolerate the offending foods if they were cooked or otherwise processed. Twenty‐eight of 34 reported reactivity to two or more plant‐derived foods. Rosaceae, tree nuts, melon and watermelon, tomato, pineapple, citrus fruits and banana were the more frequently offending foods. Conclusion Profilin should be considered a clinically relevant food allergen. Allergy to melon, watermelon, tomato, banana, pineapple and orange may be considered as a marker of profilin hypersensitivity. This study underlines the clinical importance of being able to diagnose hypersensitivity to single food allergenic proteins by SPT, particularly when the relevant food allergen sources contain several allergens that show different chemical/physical features and, hence, completely different risk profiles.     

The prevalence of latex allergy in children seen in a university hospital allergy clinic

Natural rubber latex allergy is responsible for a wide spectrum of clinical symptoms, ranging from rhinoconjunctivitis to severe anaphylaxis, in both adults and children. An association between allergy to latex and allergy to various fruits has been reported. This study investigated the prevalence and clinical significance of latex sensitization in children seen in a university hospital allergy clinic. A total of 453 consecutive children were screened in a 7-month period. A detailed clinical history with particular attention to the past surgical history and the eventual presence of latex- or food-induced allergic symptoms was obtained. Skin prick tests (SPT) for the more important inhalant allergens and foods were performed on all children. In patients with positive latex SPT, latex challenge and additional SPT for some fresh foods (avocado, pineapple, apricot, grape, banana, pear, apple, orange, almond, and chestnut) were also performed. RAST for the same food antigens, as well as patch test with latex and a standard battery of contact allergens, was also done. Of 326 atopic children, 10 (3%) presented positive skin test to latex, but only five (1.5%) also had a positive clinical history to latex exposure. Latex challenge was positive in 3/9 positive-latex-SPT children. None of the nonatopic children had positive skin test to latex or symptoms to latex exposure. A history of previous surgery was found in 5/10 positive-latex-SPT children, in 63/316 negative-latex-SPT atopic children (P<0.05), and in 23/127 nonatopic children. RAST to latex was positive in 5/10 positive-latex-SPT children. Associated fruit-specific IgE (SPT and/or RAST) were found in all latex-symptomatic children and in 2/5 latex-asymptomatic children. Apple, kiwi, and chestnut were the most common SPT-positive foods. Only one patient with clinical allergy to latex and positive skin tests to fruits had a history of clinical symptoms after ingestion of kiwi and orange. The natural history of the positive-latex-SPT children without clinical reactions to latex exposure and the clinical significance of the association of latex and fruit sensitivity require further studies.