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Estimates of the incidence of occupational asthma may be derived from surveillance schemes established in several countries. SHIELD is a voluntary surveillance scheme for occupational asthma in the West Midlands, a highly industrialized region of UK. The aim of this study was to estimate the general and specific incidence of occupational asthma in the West Midlands in 1990-97. The annual incidence was 41.2/million. There was a two fold difference in the incidence by sex (male 59.6/million/yr; female 27.4/million/yr). The highest annual incidence (53.2/million) was observed in the age group 45-64 yr (male) and 45-59 yr (female). Spray painters were the occupation at the highest risk of developing occupational asthma, followed by electroplaters, rubber and plastic workers, bakery workers and moulders. Although the percentage of reported cases was low among healthcare workers, there was a raising trend. Isocyanates still remained the most common causative agents with 190 (17.3%) out of the total 1097 cases reported to the surveillance scheme in seven years. There was a decrease in the reported cases due to colophony (9.5% to 4.6%), flour & wheat (8.9% to 4.9%). There was an increase of reported cases due to latex (0.4% to 4.9%) and glutaraldehyde (1.3% to 5.6%). The serial mesurement of peak expiratory flow at and away from work was the most used method of diagnosis to confirm the occupational cause of asthma. Specific bronchial challenge test with the occupational agents were used when the serial measurement of peak expiratory flow was not able to confirm undoubtdely the diagnostic suspicion or when it was difficult to identify the possible causative agent due to multiple exposures in the workplace. Following diagnosis, 24% of the patients were moved away from exposure within the same workplace in 1997, compared to 15.8% in the previous years. Those remaining exposed to the causative agent in the same workplace decreased from 28.3% to 17.7% between 1990-97. The surveillance of occupational asthma trough this voluntary scheme has allowed to monitor the incidence of the disease in the region and to identify clusters of cases, where control measures are a priority.

Background: The prevalence of food allergies increases, relating to diet modifications. The consumption of new foods--exotic foods or foods originally used for animal feed, new proteins, neo allergens due to the use of new technologies and soon, Genetically Modified Foods--are in the spotlight., Objective: It is essential to develop a system of food allergy vigilance encompassing the full range of foods being consumed. Understanding this imperative leads logically to the suggestion of developing an allergy vigilance network taking advantage of the ongoing experience of allergists "on the ground"., Methods: The French Allergy Vigilance Network is subscribed to by 302 allergologists (267 of whom are French). The aims of the Network are to record cases of severe anaphylaxis, to establish an epidemiological data bank from prospective multicenter studies, and to monitor the allergic risk from novel foods., Results: In 2002, 107 cases of severe anaphylaxis were recorded: anaphylactic shock--59.8% (one fatal), systemic reaction--18.7%, laryngeal angio-edema--15.9%, acute severe asthma--5.6% (one fatal). The main allergens identified were peanuts, nuts, shellfish, lupine flour and wheat flour. Action has been taken as a result: information by industry on inadequate labeling, withdrawal of wrongly labeled batches, and university hospital centers have been encouraged to establish the allergenic safety of their catering services., Conclusion: Setting up such a network in other countries would lead to a significant advance in knowledge of the peculiarities of allergies relating to a wide variety of eating habits.

We propose a novel method to produce hypoallergenic wheat flour suitable for patients allergic to wheat by using enzymatic fragmentation with cellulase and actinase. The hypoallergenic flour displayed potent inhibitory activity against allergen absorption and actively suppressed allergic reactions, probably inducing oral tolerance. The results suggest that hypoallergenic wheat flour has allergy-suppressive effects without inducing side effects.

Background: Skin prick tests (SPTs) play an important role in the diagnosis of baker's asthma and in the investigation of sensitization frequencies in field studies. It was the aim of our study to compare different SPT solutions for wheat and rye flour sensitization and to assess the validity of test results., Methods: Skin prick tests with wheat and rye flour were performed in parallel with extracts from different companies and compared with the results of bronchial challenge tests with both flours (69 rye flour and 51 wheat flour challenge tests). Additionally, specific immunoglobulin E (sIgE) to wheat and rye flour were tested. SPT solutions were analysed for protein content and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)., Results: Skin prick test solutions for diagnosis of wheat and rye flour sensitization from three companies differed in protein concentrations and composition with the consequence of widely differing SPT results. Sensitivity of SPTs in comparison with allergen-specific bronchial challenge as a gold standard was between 40 and 67%, specificity was between 86 and 100%, the positive predictive value (PPV) ranged from 81 to 100% and the negative predictive value (NPV) from 44 to 70%. These numbers were only marginally affected by using a combination of challenge test result and sIgE value as a more specific gold standard., Conclusion: Improvement and standardization of SPT extracts for wheat and rye flour is highly recommended.

Objectives: The purpose of the study was to compare cytological and biochemical changes in nasal lavage fluid induced by wheat flour inhalatory challenge in bakers with allergic rhinitis and with asthma accompanied by rhinitis., Materials and Methods: A single-blind, placebo controlled study was conducted in 64 bakers with allergic rhinitis (n = 17), bronchial asthma and rhinitis (n = 24) and without occupational allergy (n = 23). Nasal washings were examined before, 30 min, 4 and 24 h after the specific provocation, wheras non-specific bronchial hyperreactivity (PC20) before and after 24 h., Results: A significant decrease in PC20 after the challenge test was observed only in patients with asthma and rhinitis. Eosinophil count and percentage, basophil count and the permeability index induced by specific provocation were significantly increased in both rhinitis patients and asthmatics. Moreover, the increase especially in total count and proportion of eosinophils as well as in the permeability index was more pronounced in subjects suffering from asthma and rhinitis than in those with rhinitis alone, although the changes were not statistically significant., Conclusions: The results indicate the applicability of the "nasal pool" technique as a simple diagnostic procedure in flour-induced airway allergy. However, the evaluation of nasal lavage fluid, although a very sensitive and specific method of diagnosing respiratory allergic disease, cannot be used to distinguish patients with upper and lower airway allergy.

Mulberry leaf is commonly used for sericulture in almost every part of the world but its potential to be utilized for human consumption is not well recognized. This paper deals with development of mulberry leaf powder and its use with wheat flour to develop paratha, the most common food item of breakfast and dinner in the Indian diet. The optimum ratio of the mulberry leaf powder and wheat flour (MLP-WF) mix for preparation of paratha on the basis of sensory quality was found to be 1:4. The protein quality of the MLP-WF mix was estimated by measuring the Protein Efficiency Ratio, and was found to be 1.82 against a casein diet for which a value of 2.44 was observed. The in vivo toxic effect of mix was studied and no adverse effect on the growth of internal organs of rats (heart, liver, kidney and testes) was found. The storage stability of the mix was estimated for a period of 2 months in polyethylene bags at room temperature. A non-significant difference was observed between paratha prepared from fresh and stored mix. This indicated that mix can be stored for a period of 2 months at room temperature without loss of quality.

Aims: To assess the prevalence of sensitisation to a range of exogenous fungal enzymes used in bakeries, and determine the relation between sensitisation and work related symptoms., Methods: Serum samples (n = 135) from a previous cross sectional study investigating the prevalence of respiratory symptoms and sensitisation to dust components, were reanalysed for specific IgE to the mixed enzymes cellulase, hemicellulase, and xylanase., Results: Eight (6%) of sera tested had detectable specific IgE to mixed enzymes (excluding fungal alpha-amylase) and 16 (12%) to fungal alpha-amylase. A significant increase (p = 0.03) in nasal symptoms was found in those workers sensitised to enzymes (including alpha-amylase and the mixed enzymes, but with or without sensitisation to wheat flour) when compared to those sensitised to wheat flour alone. Both groups had significantly greater levels of nasal symptoms in comparison to those with no evidence of sensitisation., Conclusions: The association between specific IgE to mixed enzymes, and an increased prevalence of nasal symptoms in individuals sensitised to enzymes, highlights the importance of measuring sensitisation to the full range of exogenous enzymes used in the baking industry, as well as to wheat flour.

This is a report of a patient with occupational hypersensitivity pneumonitis (HP) caused by Konjak flour and powdered Hijikia fusiforme. A 56-year-old man had worked as a Konnyaku manufacturer for 38 years, and suffered from dyspnea on exertion. Konnyaku is a paste made from Konjak flour, powdered Hijikia fusiforme, quicklime, and powdered scallop shell. The diagnosis of HP was confirmed immunologically by the detection of serum precipitins to powdered Hijikia fusiforme, and by the positive result of in vitro lymphocytic proliferative response for Konjak flour using peripheral blood lymphocytes. To our knowledge, this is the first case report of Konnyaku manufacturer's lung.

Background: Bakery workers may develop IgE-mediated allergy to liquid and aerosolized hen's egg proteins that are commonly used in the baking and confectionery industries., Methods: We studied four bakery workers who had work-related allergic respiratory symptoms upon exposure to egg aerosols. The causative role of egg proteins in their respiratory symptoms was investigated by immunologic and specific inhalation challenge (SIC) tests., Results: Skin prick tests to egg white extract and to lysozyme gave positives responses in all the subjects, to ovalbumin in two, to ovomucoid in one and to egg yolk in two subjects. They were also sensitized to wheat, rye and barley flours. Specific IgE determinations to egg white were positive in all patients, to lysozyme in two, to ovalbumin in three, to ovomucoid in two and to egg yolk in two of them. Methacholine inhalation tests revealed bronchial hyperresponsiveness in all workers (PC20 < 16 mg/ml). SICs were performed with aqueous extracts of lysozyme (n = 4), ovalbumin (n = 2) and ovomucoid (n = 1), which elicited isolated early asthmatic reactions in all subjects. Double-blind, placebo-controlled, oral challenge tests with raw egg white were positive in three subjects., Conclusions: These bakery workers had developed IgE-mediated occupational asthma to hen's egg white proteins.

Purpose of Review: Wheat is among the six foods responsible for approximately 90% of food allergies in children, and in recent years wheat has been increasingly recognized as a cause of food-dependent, exercise-induced anaphylaxis. Wheat flour is an important cause of baker's asthma, a well-known occupational respiratory allergy to inhaled flour. This review outlines the diverse clinical manifestations of IgE-mediated wheat hypersensitivity and summarizes recent advances in characterization of clinically significant allergens., Recent Findings: Only a few of the numerous wheat proteins recognized by IgE of sensitized individuals have been characterized at the molecular level. Characterized allergens causing baker's asthma include several water/salt-soluble wheat proteins, however sensitization patterns show a great degree of individual variation. The insoluble gliadins have been implicated in IgE-mediated allergy to ingested wheat, and omega-5 gliadin has been identified as a major allergen in wheat-dependent, exercise-induced anaphylaxis. The presence of IgE to purified omega-5 gliadin in children was highly predictive of immediate clinical symptoms on oral wheat challenge., Summary: Diagnostic skin prick and in-vitro tests measuring sensitization against water/salt-soluble wheat proteins have poor predictive values. Quantification of gliadin-specific IgE in serum or skin prick testing with gliadin could serve as an additional tool in the diagnostic work-up of allergy to ingested wheat.

Objective: To evaluate the prevalence of respiratory symptoms, ventilatory function disorder and immediate hypersensitivity reactions in a population exposed to flour and cereal dusts in five flour mills in Morocco., Methods: The study of 373 exposed and 301 non-exposed subjects consisted of an analysis of working conditions and a medical survey., Results and Conclusion: The prevalence of clinical respiratory symptoms was 64.1% among exposed subjects and 41.2% among non-exposed subjects. Cough, expectoration, rhinitis, conjunctivitis, dermatitis, asthma and chronic bronchitis were more frequent among mill-workers. Spirometry was abnormal in 31.6% of those exposed: anomalies were found in both flow and volume. Among exposed subjects with a ventilatory disorder, 77.9% had only small airways syndrome or a light deficit. Smoking was the cause of excess morbidity. Skin prick tests were positive for at least one allergen in 65.4% of exposed compared to 27.2% non-exposed subjects. The prevalence of positive skin tests to occupational allergens alone was higher among those exposed (42.4%) than among the non-exposed (9.9%). The implementation of adequate medical and technical prevention may reduce this risk.

Cassava flour is the main dietary carbohydrate source in the Amazonian region. The cariogenic potentials of the two main kinds of cassava flour - 'seca' and 'd'água' - were evaluated in vivo and in vitro. A sweet made from a regional fruit (cupuaçú) and a species of local fish (tambaqui) were used as positive and negative controls, respectively. For in vivo evaluation of dental plaque acidogenicity, the study had a crossover design, in four legs, with 19 volunteers in four treatment groups. Dental plaque pH was determined by the microtouch method before and for 60 min after food consumption. For in vitro evaluation, stimulated saliva of each volunteer was incubated with the food and pH variation was determined over 4 h. Carbohydrates were chemically determined in the flours and the majority was found to be water-insoluble. In vivo, plaque pH decreased significantly after the consumption of the sweet (p < 0.05), increased after the fish (p < 0.05), but did not change after intake of the flours (p > 0.05). In vitro, the flours were slowly fermented by bacteria present in saliva. The in vivo and in vitro findings suggest that, in the form that the main cassava flours from the Amazonian region of Brazil are customarily eaten, they may be considered to have no or very low cariogenicity., (Copyright 2002 S. Karger AG, Basel)

A total of five hundred Bakery workers were studied to assess occupational induced lung impairment as a result of exposure to grain and flour dust. Occupational related symptoms were recorded using structured questionnaire. Age and sex matched controls consisting of 500 University College Hospital (UCH) Ibadan workers and students were used. They were apparently healthy and work and live at places free of fumes and smoke. Peak expiratory flow rate (PEFR) was measured in all subjects. However, full spirometry work up was done on 100 bakery workers and 100 control subjects that had been selected using simple random sampling technique. The most frequent pulmonary symptoms among the bakery workers were sneezing and running nose (53.30%) and periodic breathlessness/chest tightness (23.16%) while the symptom of cough/phlegm present in (21.53%) of the subjects. The mean PEFR of the bakery workers (463.20 + 51.39 L/ min) was significantly lower (P < 0.0001) than that of the control subjects (538.0 + 47.23 L/min). Similarly, the mean values of FEV1, FVC and FEV1% were also significantly lower than the control subjects. The findings indicate that respiratory symptoms are common during the working hours among the bakery workers and 23.16% of the subjects studied suffered some degree of airway obstruction.

Specific bronchial challenges provide information about the relationship between inhaled dose of allergen and change in lung function, but the intermediate pathways remain largely obscure. The aim of this study was to investigate the relationships between the early asthmatic response and 1) the inhaled dose of wheat flour, 2) the concentration of wheat flour, 3) the duration of the exposure, and 4) the deactivation of inhaled allergens and mediators. Thirty-one patients with occupational asthma to wheat flour were studied. Particle aerosols were generated by a computer-controlled aerosoliser and the results were expressed as the provocative dose causing a 20% fall in forced expiratory volume in one second (FEVi) (PD20). The cumulative dose (from the beginning of the challenge), the last inhaled dose, and an estimated dose (taking into account exponential deactivation), were calculated. Twenty patients had high reactivity to flour (reaching a PD20 value). Eleven patients had intermediate reactivity (no measurable PD20 but significantly greater fall in FEV1 compared with lactose challenge). A better correlation between change in FEV1 and dose was obtained for the estimated dose than for the cumulative or last inhaled dose. The bronchial response to wheat flour can be measured by the individual specific hyperreactivity and is expressed by provocative dose of flour. However, deactivation of the allergen and mediators has to be taken into account. This problem can be addressed by using a mathematical model.

Lupin flour is used in human food for its high quality nutritional and functional qualities. The frequency of crossed allergy between lupin flour and peanuts, both members of the family of Leguminosae, is strong, since 68% of patients who are allergic to peanut have shown positive reactions to lupin flour when tested by TPO-DA. Cases of isolated allergy to lupin flour without pre-existence of peanut allergy as well as workplace asthma by inhalation are also rarely seen. The specific allergens of lupin and those that participate in crosses with peanut have been studied by SDS-PAGE and immunoblot. The diversity of allergens contained in different lupin flour has also been studied. Further, the detection of lupin flour in a "pizza" flour which induced a strong allergic reaction exposed its eventual implication as a masked allergen.

The diagnosis of occupational asthma is usually performed in epidemiology using a combination of symptoms and bronchial hyperresponsiveness, while in a clinical setting the 'gold standard' for the diagnosis of occupational asthma is the specific bronchial challenge test in the laboratory The aim of this study was to detect new cases of flour-induced occupational asthma (OA) in a group of workers exposed to grain and/or flour dust, by means of a step-by-step approach, as used in a clinical setting. In an epidemiological study, III millers and 186 bakers were examined by means of questionnaire, pulmonary function tests and skin-prick tests (SPT) to common allergens and to wheat flour dust extracts. From the whole sample, 82 subjects who showed asthma-like symptoms in the questionnaire and/or low forced expiratory volume in 1 sec (FEV1) were selected. Selected subjects underwent methacholine challenge test, and hyperreactive subjects underwent specific bronchial challenge with flour dust in the laboratory. Sixty-two of the selected subjects performed the methacholine challenge test, and 22 (33 8%) were hyperreactive (PD20 FEV1 <1 mg of methacholine). Fifteen of 22 hyperreactive subjects underwent specific bronchial challenge test (s BCT) with flour dust; a positive response was elicited in six subjects. These subjects can be diagnosed as having flour-induced occupational asthma. Atopy and skin sensitivity to flour was partially related to the response to flour bronchial challenge. Bronchial hyperreactivity can be observed in a small percentage of subjects with asthma-like symptoms and/or low FEV1, and a positive response to s BCTwas observed in a subgroup of hyperreactive subjects.Therefore, using these selection criteria, a diagnosis of flour-induced OA, as commonly performed in a clinical setting, can be performed in few previously undiagnosed subjects.This approach could be relevant for an early diagnosis ofoccupational asthma.

Food allergy to wheat flour is a pathology that is found less frequently than coeliac disease or respiratory allergy to flour; it seems however to be a constant argument. Our study used a panel of 28 patients diagnosed with food allergy to wheat flour. Our objective was to characterise the reactivity of type IgE and IgG antibodies of these patients with regard to the different classes of proteins of wheat flour so as to establish an antigenic profile of the allergens of wheat in the framework of food allergy to flour. Our results show the implication of different classes of wheat proteins and notably the major reserve proteins (gliadins and glutens) in food allergy.

Observatoire National des Asthmes Professionnels (ONAP) was created in 1996 by two French professional societies to estimate the incidence of occupational asthma and to promote preventive measures against it. Occupational and chest physicians were asked to report newly diagnosed cases of work-related asthma and reactive airway dysfunction syndrome (RADS), the information collected included age, sex, occupation, suspected causal agents and diagnostic methods. In 1997, 82.3% of 559 cases reported (64% males, mean age 36 +/- 13 yrs) involved occupational asthma, 4.7% RADS and 12.7% atypical asthma syndromes. Incidence rates (expressed as number of cases per million workers) showed a regional variation that ranged from 4 to 73 (national mean: 25.7). The most frequently suspected agents were flour (23.3%), followed by isocyanates (16.6%), latex (7.5%), aldehydes (5.5%), and persulphates (4.1%). Occupations at risk were bakers (23.9%), healthcare workers (12%), painters (9.1%), hairdressers (5.2%), wood industry workers (4.8%) and cleaners (3.5%). These results are compared to those of other systems set up in Europe and North America. Because of the considerable bias inherent in a surveillance system based on voluntary, reporting, the number of occupational asthma cases reported is probably lower than the real incidence. Nevertheless, the French National Observatory for Occupational Asthma encourages physician awareness of occupational asthma and provides an estimate of its incidence and aetiologies in France.

The aim of the study was to evaluate the risk factors for hypersensitivity to occupational allergens in apprentice bakers. The study group comprised 287 persons. A questionnaire survey, as well as skin prick tests (SPT) with common and occupational allergens were performed in all subjects prior to occupational exposure and one and two years after starting vocational training. In addition, the total IgE level was evaluated in all of them at the beginning of the study. In selected cases, specific anti-flour and alpha-amylase IgE were estimated. Almost 2% of the study subjects showed positive SPT with occupational allergens before vocational training. After two years of occupational exposure, the occurrence of at least one positive SPT increased from 19.2 to 30.7%, including common (from 18.8 to 30%) and occupational (from 1.7 to 12.9%) allergens. In 18.1% of subjects, hypersensitivity to occupational allergens assessed by positive SPT, and/or the presence of antigen specific IgE developed during the study period. Logistic regression analysis revealed that positive SPT with common allergens is a significant risk factor for the development of hypersensitivity to occupational allergens (OR = 9.06, 95% CI: 2.53-32.46). The results of the study suggest that skin prick tests with common and occupational allergens should be performed in bakers prior to occupational exposure. The outcome of the tests should enable better identification of subjects at the highest risk of occupational allergy and their referral to more frequent screening. A relatively high prevalence of positive SPT with occupational allergens (2%) at the beginning of vocational training should be taken into account to avoid possible future diagnostic mistakes.

Background: The involvement of IgE-mediated hypersensitivity reactions in the genesis of gastrointestinal symptoms after ingestion of foods containing wheat has been rarely reported., Objective: To detect IgE specifically binding to wheat proteins in the sera of atopic and non-atopic patients suffering from gastrointestinal symptoms after ingestion of wheat and to evaluate the reliability of skin prick test and CAP in the diagnosis of food allergy to wheat., Methods: The sera of patients (10 atopic and 10 non-atopic) previously diagnosed as suffering from irritable bowel syndrome and complaining of symptoms after wheat ingestion were analysed by immunoblotting for IgE binding to water/salt-soluble and insoluble wheat flour proteins., Results: All the atopic patients and only one of the non-atopic patients were positive to wheat CAP. For the patients tested, skin prick test was positive for all the atopic patients and for only one of the non-atopic patients. However, immunoblotting experiments showed the presence of specific IgE to wheat proteins in all the patients. Ten out of 11 of the wheat CAP-positive patients had IgE binding to a soluble 16-kDa band, but the same band was recognized, in a slighter way, by only two out of nine of the wheat CAP-negative patients. Moreover, although almost all of the patients were negative in CAP testing with gluten, 19 out of 20 recognized protein bands belonging to the prolamin fraction., Conclusions: For the atopic patients the positivity to skin prick test and CAP to wheat was in accordance with the immunoblotting results and a food allergy to wheat could be diagnosed. In these patients a major allergen was a 16-kDa band corresponding to members of the cereal alpha-amylase/trypsin inhibitors protein family, the major allergens involved in baker's asthma. In the non-atopic patients the positive immunoblotting results contrasted with the responses of the allergologic tests, indicating that the allergenic wheat protein preparations currently used are of limited value in detecting specific IgE to wheat and that the fraction of irritable bowel syndrome (IBS) patients with food allergy may be larger than believed.

Background: although grass pea belongs to the leguminoseae family, allergic reactions to its flour have rarely been described. Clinical and immunological studies were performed to confirm a type I hypersensitivity mechanism in a case of occupational asthma to grass pea flour exposure, used in the industrial processing of parquet., Methods: occupational asthma was diagnosed according to patient history, PEFR monitoring and a specific bronchial challenge test. Skin prick test with an aqueous grass pea flour extract, specific IgE determinations (CAP assay) and IgE immunoblot tests were performed., Results: skin prick test with the extract showed a positive immediate response, and negative response in controls. Specific IgE to grass pea was positive (9.57 KU/l). Immunoblotting demonstrated the presence of specific serum IgE that recognized 3 proteins in the extract (MW 46, 32 and 28 kDa). PEFR monitoring showed positive results. Bronchial challenge test with the extract elicited an isolated immediate response., Conclusions: as far as we know this is the first time that IgE mediated occupational asthma caused by grass pea is reported and it is also the first time that its allergens are characterized. Grass pea flour might constitute a relevant occupational allergen in this unreported source of exposure in parquet manufacturers.

Background: Allergy to insects is common. However, few reports cover occupational sensitization to flour moth (Ephestia [syn. Anagasta] kuehniella). We describe a baker who suffered from IgE-mediated occupational respiratory allergy to flour moth., Methods: The skin prick test (SPT) and serum IgE tests were used to evaluate the patient's sensitivity to flour moth. Allergen cross-reactivity with mites was evaluated in IgE-inhibition studies. Clinical sensitivity was evaluated by nasal challenge test. Pulmonary function tests were repeatedly monitored., Results: SPT with flour moth gave a 6-mm wheal, and an elevated level of flour moth-specific IgE was measured in the patient's serum (1.9 PRU/ml, RAST class 2). Immunoblotting with the patient's serum revealed at least seven heavy IgE-binding bands with molecular masses of 22, 35, 43, 53, 65, 77, and >86 kDa in the extract of flour moth. Allergen cross-reactivity with mites was demonstrated in inhibition studies. Immediate-type allergy to flour moth was confirmed by nasal challenge. Increased daily variability of PEF values was observed during workplace exposure., Conclusion: A baker's occupational respiratory allergy to flour moth was confirmed.

Background: baker's asthma is a well-known occupational lung disease which usually develops in adults. We report the case of a two years old boy who suffered from asthma, urticaria and atopic dermatitis for twelve months, whose symptoms were associated to visits to his grandfather's bakery., Methods and Results: skin prick tests (SPT) were made to dust mites, moulds, flours, alfa-amylase and egg. It was also determined total IgE and specific IgE antibodies to alfa-amylase and flours. Subsequently, a challenge test was carried out with wheat flour. The SPTs were positive to flours, alfa-amylase and egg. The determination of specific IgE antibodies showed 2.64 kU/L to wheat, 0.79 kU/L to glyadin and 2.98 kU/L to alfa-amylase. The patient developed asthma and rhinitis after manipulating wheat flour for 10 min., Conclusions: we demonstrated a type I hypersensitivity to wheat flour and alfa-amylase in a two years old child by SPT, specific IgE antibodies and challenge test. This case in the childhood equivalent of occupational baker's asthma.

Background: Exposure to occupational agents can induce eosinophilic inflammation in subjects with occupational asthma (OA). It might also induce nonspecific changes in airway inflammation in subjects without OA., Objectives: We sought to investigate the changes in airway inflammation induced by exposure to occupational agents in subjects with and without OA and to determine which changes in sputum eosinophil numbers and bronchial responsiveness to methacholine should be regarded as clinically significant for predicting a 20% fall in FEV(1)., Methods: We performed specific inhalation challenges (SICs) in 3 groups of subjects: subjects reporting a history consistent with OA with a positive SIC response (n = 17); subjects reporting a history consistent with OA with a negative SIC response (n = 14); and asthmatic subjects without any history of OA (n = 10). Induced sputum and methacholine challenges were performed at the end of the control day and again at the end of the last day of exposure; the last day of exposure was always performed in the laboratory., Results: There was an increase in median sputum eosinophil and neutrophil numbers in subjects with positive SIC responses. Cell counts remained unchanged after exposure in asthmatic subjects without OA. A combination of a greater than 0.26 10(6)/mL increase in sputum eosinophil numbers and a decrease in the concentration of methacholine inducing a 20% fall in FEV(1) of at least 1.8-fold compared with baseline values predicted a 20% fall in FEV(1) in 96% (95% CI, 70%-99%) of patients., Conclusion: Exposure to occupational agents per se does not induce airway inflammation. Changes in both sputum eosinophil counts and methacholine responsiveness are satisfactory predictors of a significant bronchial responsiveness to occupational agents.

Wheat is a food allergen which occasionally causes anaphylactic reactions exclusively in young children. There is very little knowledge of the clinical outcome in cases of food-related anaphylaxis and the differences in the allergenic protein components of food involved, comparing individuals who have suffered from an anaphylactic reaction with other individuals. The objectives of the present study were to examine the clinical features of 7 young children who had experienced anaphylactic reactions after ingesting wheat flour-containing products, and to analyze the allergens in wheat flour responsible for the anaphylactic symptoms. We measured the total IgE levels and the levels of IgE antibodies specific to wheat flour and performed IgE immunoblotting, comparing the sera from these children with sera from patients with atopic dermatitis. All sera from children who had experienced anaphylactic reactions were found to be positive for IgE specific to wheat. IgE immunoblotting revealed that 3 of these 7 children had sera showing reactivity to components of the salt-soluble protein fraction (16, 35--67 and 94 kD) and salt-insoluble protein-containing fraction (16, 38 and 70 kD) and 4 had no sera showing reactivity to components of the salt-soluble fraction. Patients with atopic dermatitis showed similar staining patterns. Various proteins in wheat flour could be allergens responsible for anaphylaxis and atopic dermatitis in infants or young children. Our findings suggest that these two clinically diverse allergic diseases do not necessarily represent responses to different allergenic proteins of wheat., (Copyright 2001 S. Karger AG, Basel)

Background: Wheat flour proteins are allergens for 60% to 70% of bakers with workplace-related respiratory symptoms., Objective: The aim of the study was to investigate the variability of IgE antibody patterns of wheat flour-sensitized bakers and to identify the most frequently recognized allergens., Methods: Water/salt-soluble wheat flour proteins from the cultivar Bussard were separated by using 2-dimensional gel electrophoresis with immobilized pH gradients. IgE-reactive proteins were identified by means of immunoblotting with sera of 10 subjects with baker's asthma. Mass spectrometric fingerprinting was used to identify the proteins most frequently recognized by IgE., Results: The IgE immunoblots obtained with 10 different sera exhibited a remarkable heterogeneity. Each patient showed an individual IgE-binding pattern with 4 to 50 different allergen spots. Altogether, more than 100 IgE-binding protein spots were detected. Nine of the predominant IgE-binding protein spots were identified by using mass spectrometric fingerprinting. The obtained masses matched 2 different isoforms of glycerinaldehyde-3-phosphate dehydrogenase from Hordeum vulgare, triosephosphate isomerase from H vulgare, and serpin, a serine proteinase inhibitor from Triticum aestivum., Conclusions: The results show a great interindividual variation of IgE-binding patterns of wheat flour proteins in baker's asthma. The clinical relevance of the identified 4 new allergens will be further investigated in the near future.

Latex is a well-known sensitizer. Prospective studies in apprentices beginning to be exposed to latex have not been carried out. We wanted to determine the incidence of skin reactivity, cutaneous symptoms, rhinoconjunctivitis (RC) symptoms, respiratory symptoms, probable occupational RC, and asthma in apprentices in dental hygiene. A total of 122 students starting a program in dental hygiene technology were recruited between 1993 and 1995. A questionnaire, skin-prick tests with common aeroallergens and latex, and assessment of spirometry and responsiveness to methacholine were carried out on entry and at follow-up visits at 20 and 32 months after the start of exposure. Of the 110 subjects who participated for at least 1 follow-up visit, skin reactivity to latex developed in 7. Cutaneous symptoms developed in 6 of the 7, RC symptoms developed in 2, and respiratory symptoms developed in 1. Five of the 7 subjects had significant changes in methacholine responsiveness and fulfilled the definition of probable occupational asthma. Sensitized subjects were more likely to be atopic and to have a previous history of asthma and respiratory symptoms on exercise than were nonsensitized subjects. Three subjects at the 20-month assessment and 4 subjects at the 32-month visit showed skin reactivity. The cumulative incidences for skin sensitization, probable occupational RC, and occupational asthma to latex were 6.4%, 1.8%, and 4.5%, respectively.

Background: The baking additives xylanase and cellulase were described as baking additives causing baker's asthma. It is not known whether monosensitization to these enzymes may occur., Methods: We present a case report of a baker with work-related asthma evaluated by skin prick test (SPT), enzyme-linked immunosorbent assay (EAST), immunoblot, EAST and immunoblot inhibition, and specific bronchial challenge. Fungal xylanase and alpha-amylase were measured by two-site enzyme immunoassays in products used by the patient at work., Results: Allergy to xylanase and cellulase was demonstrated by SPT, EAST, immunoblot and specific bronchial challenge (for xylanase only). No sensitization to alpha-amylase could be demonstrated, but there was a weak flour allergy as documented by EAST and immunoblot and a positive occupational-type challenge with high concentrations of rye flour. Four baking additives contained measurable amounts of fungal alpha-amylase and xylanase, without a correlation between these enzymes., Conclusions: We conclude that occupational asthma due to the baking additives xylanase and cellulase may occur without concomitant sensitization to alpha-amylase and only weak sensitization to flour., (Copyright 2001 S. Karger AG, Basel)

Objective: Quantitative risk assessments have been made for wheat dust and allergen exposure and wheat sensitization using classical epidemiological approaches based on simple categorizations in exposure groups. Such analyses suggest the existence of an exposure threshold level for wheat specific sensitization and were used as input in recently conducted risk assessments for wheat flour by the American Conference of Governmental Industrial Hygienists and the Dutch Expert Committee on Occupational Standards. More advanced statistical analyses were applied using generalized additive modeling and smoothed plots to evaluate the shape of the exposure response relationship in greater detail and evaluate the presence of exposure thresholds., Methods: Data were used from a recently conducted epidemiological study in bakery workers. Information was available on wheat sensitization (IgE antibodies), inhalable dust levels and wheat allergen levels. Initial analyses were based on simple exposure categorizations for inhalable dust and allergen exposure. A more detailed analysis using non-parametric generalized additive models (GAM models) and smoothing plots allowed inspection of the presence of an exposure threshold of evaluation of 'no' or 'lowest observed effect levels' (NOELs, LOELs) using exposure data on the individual level., Results: All analyses showed an increasing sensitization risk with increasing exposure. The classical epidemiological analyses gave evidence for the existence of an exposure threshold or 'no observed effect level (NOEL)' for specific wheat sensitization between 0.5 and 1 mg/m3 of inhalable dust. The more advanced analyses did not suggest any evidence for the existence of an exposure threshold. However, estimates of a LOEL obtained by considering an arbitrary increase in sensitization risk between 1.5 and 2 as undesirable, were close to the NOEL from the classical analyses and would therefore not lead to an essentially different exposure limit. The criterion of an increase in wheat sensitization risk was based on the risk in non-wheat dust exposed populations., Conclusion: Exposure response modeling using different classical epidemiological approaches and advanced statistical methods resulted in health based LOEL or NOEL estimates within a relatively close range. But when sensitization accompanied by asthma or rhinitis symptoms was considered as critical endpoint, steeper exposure-response relationships were observed which would lead to lower LOEL values.

Objectives: To estimate the incidence of specific IgE sensitization and allergic respiratory symptoms among UK bakery and flour mill workers; and to examine the roles of flour aeroallergen and total dust exposures in determining these outcomes., Methods: A cohort of 300 new employees, without previous occupational exposure to flour, were followed prospectively for a median (range) of 40 (1-91) months. Cases-defined as those developing work-related symptoms or a positive skin prick test to flour or alpha-amylase during follow up--were compared with controls, matched for duration of employment. Exposures to flour aeroallergen and total inhalable dust were estimated using a questionnaire and personal sampling techniques., Results: Incidence rates for work-related eye/nose and chest symptoms were 11.8 and 4.1 cases per 100 person years (py), respectively. Fewer employees developed positive skin prick tests to flour (2.2 cases per 100 py) or alpha-amylase (2.5 cases per 100 py). Positive skin tests to occupational allergens were more common among those with new work-related symptoms. There were clear relationships between the risks of developing work-related symptoms or a positive skin prick test and three categories of estimated exposure to total dust or flour aeroallergen. Atopic employees were more likely to develop a positive skin prick test-but not work-related symptoms. These findings were unaffected by age, sex or cigarette smoking., Conclusions: In this population, many work-related symptoms which develop after first employment in modern UK bakeries or flour mills were not accompanied by evidence of IgE sensitization to flour or alpha-amylase. Although average dust exposures were within current occupational standards, the risks of development of upper and lower respiratory symptoms and of specific sensitization were clearly related to total dust and/or flour aeroallergen exposure. The incidence of work-related chest symptoms in the presence of a positive skin test to flour or alpha-amylase in this setting was approximately 1 case per 100 py.

A study of the oral health of workers in flour mills was carried out. The examined group consisted of 40 males and 8 females, currently employed at flour mills. The results of the research indicate the necessity of intensification of stomatological care among mill workers.

Objectives: The aim of the study was to follow the similarities and differences, of cellular and mediator changes and mucosal/vascular permeability in the upper and lower airway after specific and nonspecific bronchial provocation, in bakers with diagnosed occupationally induced allergy affecting the airway. In addition, the authors try to find whether there is a relationship between cellular changes in nasal and bronchoalveolar lavage, and bronchial hyperreactivity., Methods: The study participants were 10 bakers with occupational bronchial asthma and allergic rhinitis. All patients were sensitized to investigated allergen-flour. Nasal- and bronchoalveolar lavage techniques were used to evaluate the changes of the cellular and mediator response (tryptase, eosinophil cationic protein, ECP) and albumin level after specific (flour) and placebo provocation. In addition. bronchial hyperreactivity for histamine, and forced expiratory volume in 1 s (FEV1) were measured after the challenge., Results: There was a significant increase in the percentage of eosinophils, basophils and albumin in nasal and bronchoalveolar lavage of occupationally sensitized bakers. A statistically significant increase in the percentage of neutrophils in bronchoalveolar lavage was observed only 24 h after the allergen challenge. The level of tryptase in nasal lavage was significantly higher during the early allergic response. The levels of ECP in both nasal and bronchoalveolar lavage were significantly increased during the late allergic response. There were also severe bronchial reactions and increase of bronchial hyperreactivity for histamine in occupationally sensitized bakers in the late phase of allergic reaction., Conclusion: Eosinophils and basophils proved to be the predominant cells in nasal and bronchoalveolar lavage of patients with occupationally induced bronchial asthma and rhinitis. The prolonged increase of albumin level seems also to be a good predictor of protracted nasal and bronchial inflammation. The results obtained confirmed that tryptase and ECP are good markers for monitoring mast cell and eosinophil degranulation during the allergic reaction. Increase of airway responsiveness reflects an eosinophil and basophil contribution to airway allergic response.

Objectives: To explore relations between two estimates of exposure to inhalable flour dust, and the incidence rates (IRs) of asthma and rhinitis in bakers., Methods: This was a retrospective cohort study among 2923 bakers. A posted questionnaire registered the disease and work history. For every year, each baker was assigned an estimate of the exposure concentration to inhalable flour dust derived from reported job-tasks and dust measurements. Exposure at onset of disease was expressed as current dust exposure concentration, and as cumulative dose of exposure to dust. A multiple Poisson regression analysis assessed the impacts of the exposure estimates on the IRs of asthma and rhinitis., Results: IRs of asthma and rhinitis increased by dust concentration at onset of disease. The IR of asthma for the bakers with highest exposure (dough makers) was 7. 3/1000 person-years in men and 6.5 in women and for rhinitis 43.4 and 38.5, respectively. There was a significant association between the dust concentration at onset of disease and the risk for asthma or rhinitis, but not of the cumulative exposure., Conclusion: The risk of asthma seemed to be increased at inhalable dust concentrations >/=3 mg/m(3) (dough making or bread forming), whereas the risk of rhinitis was increased at all concentrations >/=1 mg/m(3), indicating an increased risk in all bakery job-tasks. The risks seemed to be less dependent on the cumulative exposure dust than the inhalable dust concentrations.

Unlabelled: Lupine flour (lupinus albus), recently authorized in France in human food, cross-reacts with peanuts. We report a case of acute asthma in a patient with allergy to peanuts., Exegesis: This patient has a severe allergy to peanuts, presenting as acute asthma. Skin prick-tests to raw and cooked lupine flour were positive. The level of specific-IgE (Allerbio, France) to lupine flour were high. Oral challenge test induced acute asthma at a dose of 965 mg of lupine flour. This quantity may be included in 100 g of bread., Conclusion: This case report points out the fact that lupine flour is a high-risk allergen in patients presenting allergy to peanuts. It is necessary to evaluate the allergenic risk of new foods before their introduction into human daily food intake and to establish a network of allergy vigilance.

Objectives: To investigate the occurrence of work related respiratory symptoms and to assess the effect of atopy in a group of trainee bakers., Methods: A prospective study of work related respiratory symptoms among 125 trainee bakers who were investigated with a questionnaire plus skin prick test with wheat flour and alpha-amylase allergens at baseline and then after 6, 18, and 30 months., Results: At the baseline examination, four students (3.2%) complained of respiratory symptoms (cough and rhinitis) when working with flours and four were skin positive to wheat flour or alpha-amylase. The incidence of work related respiratory symptoms was 3.4% at 6 months, and the cumulative incidence was 4.8% and 9.0% at 18 and 30 months, respectively. The incidence of skin sensitisation to occupational allergens was 4.6% at 6 months and the cumulative incidence was 4.6% at 18 months and 10.1% at 30 months. The generalised estimating equation approach to longitudinal data showed that work related respiratory symptoms in the study population was significantly associated with a personal history of allergic disease (odds ratio (OR) 5.8, 95% confidence interval (95% CI) 1.8 to 18.2) and skin sensitisation to wheat flour or alpha-amylase (OR 4.3, 95% CI 1.2 to 14.9). Atopy based on prick test was not related to the occurrence of work related respiratory symptoms over time (OR 1.1, 95% CI 0.3 to 3.8)., Conclusions: Personal history of allergic disease is a predisposing factor for the development of symptoms caused by exposure to wheat flour and may be a criterion of unsuitability for starting a career as a baker. Atopy based on the skin prick test is useful for identifying subjects with allergic disease, but should not be used to exclude non-symptomatic atopic people from bakery work.

Baker's respiratory allergy is reported as one of the most common forms of occupational allergy in many countries. At the first stage of a three-year study of risk factors of occupational allergy we investigated the symptoms reported, and the results of skin prick tests (SPT) to common and flour allergens in 461 current apprentice bakers from three different regions of Poland before starting occupational exposure. The occurrence of cough was reported by 14 subjects (3%), dyspnoea by 4 (0.87%), rhinitis by 18 (3.9%), conjunctivitis by 12 (2.6%) and skin symptoms by 12 subjects (2.6%). Generally, 48 subjects (10.41%) reported at least one symptom, which might suggest the existence of allergic disease. Positive SPT to at least one allergen was found in 99 subjects (21.5%), including 82 subjects (17.78%) with positive SPT to common allergens, 13 subjects (2.81%) to flour allergens and 4 subjects (0.88%) sensitised only to Dermatophagoides farinae. The statistical analysis revealed significant correlation between positive SPT to common allergens and reported rhinitis and conjunctivitis, and between positive SPT to occupational allergens and reported dyspnoea. Moreover, a significant correlation between positive SPT to D. pteronyssinus and D. farinae was found. In our opinion, the results of SPT should be very carefully examined, when diagnosing occupational allergy, as in some apprentice bakers positive results of SPT to flour allergens are found before vocational training. In all apprentice bakers, SPT to common and occupational allergens should be performed before starting occupational exposure. It would ensure the exclusion of subjects already sensitised to occupational allergens. Positive SPT to Dermatophagoides farinae has a very limited value in recognising baker's allergy.