Asthma, rhinitis, other respiratory diseases Wine-induced asthma: A placebocontrolled

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1 Asthma, rhinitis, other respiratory diseases Wine-induced asthma: A placebocontrolled assessment of its pathogenesis Hassan Vally, BSc (Hons), Amanda Carr, BAppSc, Jacque El-Saleh, RN, and Philip Thompson, FRACP Perth, Australia Background: The sulfite family of food additives has been implicated in the pathogenesis of wine-induced asthma. However, the evidence supporting this is weak, and because wines have many hundreds of components, nonsulfite-associated mechanisms may also play a role. Objectives: The aim of the study was to assess the potential sensitivity of persons with asthma to nonsulfite components in wine by using low-sulfite wine challenges. Methods: Sixteen adults with a strong history of wine-induced asthma were challenged with both low-sulfite red and white wines and wine-placebo drinks. Challenges were performed double blind, using a Latin square design, with lung function being assessed before the challenge and at 5, 10, 15, 30, and 60 minutes after the challenge. Subsequently, single-blind challenges with high-sulfite white wine were also completed in 10 individuals whose lack of reactivity to low-sulfite white wine suggested possible reactivity to sulfite additives. Results: The mean FEV 1 ; forced expiratory flow, mid-expiratory phase; and peak expiratory flow of subjects to low-sulfite red and white wines and red and white placebo wines were not significantly different. Furthermore, with a predetermined criterion of a fall in FEV 1 of more than 15% representing a positive challenge, only one individual exhibited a positive reaction in the presence of a negative response to placebo. Only 2 of the 10 test individuals who were challenged with a high-sulfite wine demonstrated a marked and rapid fall in FEV 1. Reactivity to low-sulfite wines appears to occur only in a small number of individuals who report sensitivity to wines, suggesting that the sulfite additives may be the major cause of wine-induced asthmatic reactions. However, direct challenge with high-sulfite wine revealed only 2 clear reactions in this asthma cohort. Conclusion: Wine-induced asthma appears to be a complex phenomenon and may involve several mechanisms that are codependent. (J Allergy Clin Immunol 1999;103:41-6.) Key words: Asthma, sulfite, wine From the Asthma and Allergy Research Unit, Department of Medicine, University of Western Australia, Queen Elizabeth II Medical Centre, Perth. Received for publication June 4, 1998; revised Aug 3, 1998; accepted for publication Aug 3, Reprint requests: Philip J. Thompson, FRACP, Asthma and Allergy Research Unit, University Department of Medicine, Queen Elizabeth II Medical Centre, Nedlands WA 6009, Australia. Copyright 1999 by Mosby, Inc /99 $ /1/93730 Abbreviations used FEF : Forced expiratory flow, mid-expiratory phase PEF: Peak expiratory flow VAS: Visual analogue scale Although many persons with asthma report wine as a trigger for worsening asthma symptoms, 1 little is known about the pathogenesis of these reactions. Some individuals report reactions to red wines only, others to white wines only; some individuals report reactions to both red and white wines, and certain individuals report reactions only to specific types or brands of wine. The understanding of the mechanisms of these reactions is further complicated by the fact that these drinks consist of many hundreds of components derived from the grapevine, yeast, and bacteria and from chemicals added during the processing steps. 2 Despite these confounding factors, the sulfites have been singled out as playing the major role in wine-induced asthmatic reactions. 3 Sulfites are produced by yeast during fermentation but are also added exogenously during manufacture because they have many roles, including the prevention of microbial spoilage and oxidation of these drinks. 4 Limited studies directly investigating the role of sulfites in wine-induced asthma have yielded equivocal results. 5,6 Furthermore, because sulfites may be associated with the triggering of asthmatic reactions in up to 10% of individuals with asthma 7,8 and because the prevalence of wine-induced asthma may be as high as 30%, 1 nonsulfite components of wine may be playing a major role in these reactions. The aim of this study was to assess whether nonsulfite components of wine may be triggering asthmatic reactions. Consequently, 16 subjects with a clear history of wine-induced asthma were challenged in a double-blind fashion with both placebo and low-sulfite red and white wines. Additional single-blind challenges were also conducted with high-sulfite wines and with specific problem wines to further delineate the pathophysiologic features of these reactions. METHODS Study design Sixteen individuals with stable asthma (13 women and 3 men; mean age, 33.2 ± 9.6 years; range, 23 to 53 years) were recruited into a double-blind, Latin-square designed, placebo-controlled study to assess the effect of wine consumption on airway narrowing. All subjects reported a history of repeated episodes of worsening 41

2 42 Vally et al J ALLERGY CLIN IMMUNOL JANUARY 1999 TABLE I. Patient details and history History of History of sulfite- Baseline Baseline Age Skin prick response Asthma wine food FEV 1 FEV 1 Patient Sex (y) Positive Brewer s yeast medications sensitivity sensitivity (L) (% predicted) 1 F 29 Y Y ba C,W Y M 27 Y Y ba R N F 30 Y Y ba R,W,C Y M 42 Y N ba,sm,bc R N F 26 Y Y ba,bc R N F 51 Y Y ba R,W,C,Ch Y F 27 Y Y ba,bu R,W,C N M 29 Y Y ba W,C N F 23 Y N ba,bc R,C N F 30 Y N ba W,C,Ch N F 25 Y N ba,bc R,W,Ch Y F 39 N N ba,th W,Ch N F 28 Y N ba R,W,C N F 28 Y N ba,bc R,W,C,Ch N F 53 N N ba,bc R,W N F 45 Y Y bc,ip,cr W,C,Ch N % predicted, Percentage of predicted value; ba, β 2 -adrenoceptor agonists; C, champagne; W, white wine; R, red wine; sm, salmeterol; bc, beclomethasone; Ch, cheap wine; bu, budesonide; th, theophylline; ip, ipratropium bromide; cr, cromoglycate. asthma symptoms within 1 hour of wine consumption, but no history of reacting to spirit-based drinks. Subjects who had liver disease or serious medical conditions, who were taking medications known to interact with alcohol, or who were pregnant were excluded from the study. Patients whose adverse reactions to wine had previously resulted in hospitalization and those who had an obvious impairment in alcohol metabolism were also excluded from the study. Clinical details of asthma were recorded for all patients, and allergen skin tests were performed with a range of common allergens. All individuals entering the study had baseline spirometry assessed (Vitalograph Ltd, Buckingham, UK) and were required to have an FEV 1 greater than 70% of predicted value or an FEV 1 greater than 1.5 L. In addition, a questionnaire was completed at entry to the study to assess the patient s sensitivity to alcoholic beverages and sulfite-containing foods. Challenge drink preparation Low-sulfite wine. Commercially available low-sulfite red and white wines (BRL Hardy Wine Co., Reynella, South Australia) were used in this study. The sulfite levels of these wines were determined by the alkimetric aspiration technique, 9 with the total sulfite concentration being measured both in our laboratory and confirmed by an independent wine analysis laboratory. The total sulfite content of the low-sulfite red wine was 3.7 ± 0.9 ppm (1.9 ppm free, 1.9 ppm bound); the total sulfite level of the low-sulfite white wine was 18.9 ± 0.9 ppm (2.1 ppm free, 16.8 ppm bound). The ph of the lowsulfite wines used in this study were consistently found to be between 3.5 and 3.7. Placebo wine. Placebo red and white wine drinks were used in this study. These drinks were an enhancement of the model wine solution used by Halpern et al 5 in their challenge studies and consisted of a wine-like base containing g/l tartaric acid, g/l sugar, and 0.06 mmol/l NaOH in sterile pure water. The red wine placebo was colored by the addition of 1 g of red Anthocyanin dye per 500 ml of this base; the white wine placebo was colored by the addition of 2 to 3 drops of a stock solution of Curcumin dye (made by the dissolution of 0.2 g of Curcumin yellow to 1 ml of water). The final placebo challenge drinks were then prepared by the addition of ml of this wine-like base to 63.5 ml of vodka (37.2% alcohol/volume). Both the alcohol content (13.5% vol/vol) and final ph of these placebo drinks (ph 3.5) were matched to that of the wines used in this study. High-sulfite wine. High-sulfite wine was created by spiking lowsulfite white wine with sodium metabisulfite (Na 2 S 2 O 5 ) to increase the sulfite concentration to 300 ppm. The addition of sulfite was facilitated through the agency of a sulfite stock solution. Confirmation of sulfite level of the high-sulfite wine was completed with the alkimetric aspiration sulfite assay and was found to be ± 12.4 ppm (238.9 ppm free, 51.7 ppm bound). Freshly made high-sulfite wine was used for each study day. A preliminary study confirmed that there was no loss of sulfite and no appreciable change in the proportion of free to bound sulfite over the period of each study day. Challenge procedure Double-blind low-sulfite wine challenge. Subjects were instructed to eat a light meal 2 hours before each challenge and to abstain from all alcoholic beverages for at least 48 hours. The use of medications was also restricted before each challenge day; short-acting β 2 -agonists were restricted for 8 hours; cromolyn/nedocromil, inhaled steroids, and anticholinergics were restricted for 12 hours; long-acting β 2 -agonists and short-acting antihistamines were restricted for 24 hours; and theophylline was restricted for 3 days before the challenge. Challenges were conducted at least 48 hours but less then 8 days apart and at the same time of day (±1 hour). The challenge on each occasion involved the steady ingestion of 175 ml of the alcoholic drink over a period of 3 minutes. All of the challenge drinks were consumed at room temperature. Baseline FEV 1 was assessed at the beginning of each study day and was required to be within 10% of the baseline FEV 1 at entry into the study. Lung function measurements were then taken at 5, 10, 15, 30, and 60 minutes after wine challenge. The best of 3 measurements was recorded for each time point. A fall in FEV 1 more than 15% from prechallenge values was predetermined as a positive response to challenge in the individual; a fall in FEV 1 of more than 25% resulted in the mandatory withdrawal of the subject from the study day and the administration of appropriate bronchodilatory therapy.

3 J ALLERGY CLIN IMMUNOL VOLUME 103, NUMBER 1, PART 1 Vally et al 43 Single-blind high-sulfite wine challenge. After excluding patients who reacted to placebo wine challenges, 10 of the remaining 14 patients undertook a high-sulfite wine challenge. Singleblind high-sulfite wine challenges were conducted in a similar fashion to the double-blind wine challenges described earlier, but with the following modifications. After equilibration for 5 minutes at room temperature, 150 ml of cooled white wine (4 o C) was consumed over a period of 5 minutes. Lung function measurements began immediately after the completion of the wine drink (5 minutes), with additional measurements at 15, 30, and 60 minutes after challenge. A fall in FEV 1 of more than 15% (from prechallenge values) was considered representative of a positive response to challenge; lung function measurements were halted if this was observed. Single-blind challenge with specific problem wines. Three subjects who had no reaction to low-sulfite wine challenges or to highsulfite wine challenges were subsequently challenged in singleblind fashion with specific wines to which they had reported reactions in the previous 12 months. Challenges were performed in a similar fashion to that described for the single-blind high-sulfite wine challenges. However, to closely mimic exposures to wines as they occur in social settings, red wines were consumed at room temperature, and white wines were consumed after being chilled to 4 C. The appropriate low-sulfite wine to which the subject had previously demonstrated nonreactivity was used as the placebo in these studies; the order of these challenges was randomized. Subjective measurement of patient responses to wine challenge After the double-blind placebo-controlled challenges to low-sulfite wines, subjects were asked to mark on a visual analogue scale (VAS) the degree to which they felt they had reacted. The VAS was anchored at the left with no (reaction) at all and at the right with much worse (reaction) than usual. All responses were recorded as a score from 1 to 100, based on the distance in millimeters from the left. Individuals were also required to assess the degree to which specific asthma symptoms were experienced, both before and after the challenge with a VAS for each of the following 4 parameters: cough, chest tightness, shortness of breath, and wheeze. Statistics The InStat statistics program (Graphpad Software, San Diego, Calif) was used to generate mean (SEM) values, and the differences between means were assessed for statistical significance with the Student t test. Correlations were determined with Spearman s rank correlation. Ethics The study was reviewed and approved by the Committee for Human Rights of the University of Western Australia. The protocol was explained, and informed consent was obtained from all subjects taking part in this study. RESULTS Subjects Twenty-two self-reporting wine-sensitive individuals with asthma were screened; of these, 16 completed the study. Of those not completing the study, 2 subjects did not meet wine-sensitivity history requirements on interview, 3 subjects were withdrawn because of unstable asthma, and 1 subject was withdrawn because of an adverse event unrelated to the study protocol. Subject details and histories of the 16 recruited subjects are summarized in Table I. Fourteen subjects were atopic as demonstrated by FIG 1. Change in FEV 1 in response to red wine (filled boxes) and red wine placebo (open boxes) in subject 3. Baseline FEV 1 is represented by the horizontal dashed line. skin prick tests, with 8 subjects reacting to brewer s yeast. The subjects histories of wine reactivity were disparate; 7 individuals indicated a history of asthmatic reactions to both red and white wines, 5 to white wines only, and 4 to red wines only. In addition, 9 individuals specifically identified cheaper brands of wine as worsening their asthma symptoms to a greater degree than more expensive wines. With the criteria of consistent asthmatic reactions to at least 2 different sulfite-containing foods, 4 subjects in this study were classified as sulfite sensitive. Double-blind low-sulfite wine challenge Lung function measurements. No significant difference was observed in the maximum fall in FEV 1, forced expiratory flow, mid-expiratory phase (FEF ), or peak expiratory flow (PEF) after challenge with each of the low-sulfite wines and respective placebo wines (Table II). However, with the predetermined criterion of a fall in FEV 1 of more than 15% as representing a positive response, 3 subjects reacted to one or more of the challenges. Subject 3 exhibited a positive reaction to the lowsulfite red wine challenge, with the FEV 1 falling 24.2% from baseline within 5 minutes (Fig 1). The other 2 positive reactors exhibited reactions to wine challenges and to one of the placebo challenges. Subject 5 exhibited a positive response to the red wine challenge, the placebo red wine challenge, and the white wine challenge, with maximum falls in FEV 1 of 29.1%, 19.0%, and 17.4%, respectively; subject 14 exhibited a positive response to the red wine challenge and the placebo white wine challenge, with maximum falls in FEV 1 of 19.4% and 18.7% for each of these challenges, respectively. Perception of reactions. The VAS responses correlated significantly with the measured maximal fall in FEV 1 (r s, 0.54; P <.0001; Fig 2). All subjects experiencing a fall in FEV 1 in response to the wine challenge indicated a significant alteration in their asthma symptoms on the VAS. In subject 3, who recorded a clear reaction to lowsulfite red wine, there was an equal increase in intensity (by 25 mm) for all 4 of the assessed asthma parameters.

4 44 Vally et al J ALLERGY CLIN IMMUNOL JANUARY 1999 FIG 2. Scattergram shows the VAS scores recorded by subjects with asthma in response to wine challenges (n = 16). Bars indicate mean values. Subjects 4, 6, 13, and 16 perceived a significant reaction to one or more of the challenges (VAS scores, 46 to 90 mm) that was not accompanied by a decline in spirometric measurements. Single-blind high-sulfite wine challenge Ten individuals who took part in the first part of this study received an additional high-sulfite white wine challenge (placebo controlled). Subjects 3 and 11 responded to the high-sulfite wine challenge and also provided a history strongly suggestive of a sensitivity to sulfite additives in foods. Both of these positive responses to highsulfite wine challenges were marked, with FEV 1 falling by more than 40% (from baseline) within 5 minutes (Fig 3). Interestingly, subject 3 reacted to the low-sulfite red wine challenge and to the high-sulfite white wine challenge but not to the placebo wines, suggesting that 2 separate pathways may underlie the sensitivity to wines in this one individual. It is also interesting to note that subjects 1 and 6, who provided a history strongly suggestive of sulfite sensitivity, did not demonstrate a significant decline in FEV 1 after the high-sulfite wine challenge (Fig 3). The lung function in subject 1 remained steady after the wine challenge; in subject 6, the FEV 1 fell rapidly by 11.2% within 5 minutes before recovering to baseline levels by 15 minutes. In subject 15, a positive reaction to the high-sulfite wine challenge was observed; however, lung function measurements (FEV 1 < 90% of baseline) and a clinical interview indicated the individual s asthma had changed considerably between this challenge and the previous low-sulfite wine challenge. Consequently, a low-sulfite wine challenge was repeated, and significantly this individual exhibited reactivity to this second challenge (Fig 4). FIG 3. Change in FEV 1 in response to high-sulfite wine challenge in subjects who provided a food history suggestive of a sensitivity to sulfites: subject 1 (open circles), subject 3 (filled boxes),subject 6 (filled circles), subject 11 (open boxes), and the average change in FEV 1 in response to low-sulfite challenge in these subjects, n = 4 (*). Baseline FEV 1 represented by the horizontal dashed line. Single-blind challenge with specific problem wines A further single-blind challenge was completed with specific brands of wine to which individuals had reported reactions in the previous 12 months. Unfortunately, many subjects found it difficult to identify the specific wine triggering their asthmatic reactions, and only 3 (of a possible 8) individuals were able to participate. Two of the 3 individuals (subjects 1 and 8) identified specific white wine triggers and did not respond to challenge; subject 15, who identified a specific red wine trigger, exhibited a reaction that was not significant (Fig 5). DISCUSSION We investigated the role of the nonsulfite components of wine in wine-induced asthmatic reactions by challenging individuals in a double-blind fashion with both red and white low-sulfite wines and wine placebo drinks. Using 3 measures of airway narrowing (FEV 1, PEF, and FEF ), we were unable to demonstrate a significant decline in the mean lung function parameters of this study group in response to a challenge with low-sulfite wines compared with placebo wines. However, defining a positive response as a fall in FEV 1 of more than 15%, we observed a reaction to low-sulfite red wine in one subject. This response was rapid in onset, with FEV 1 declining by 24.2% in 5 minutes, and suggested that this individual may be sensitive to a component present in low-sulfite red wine. One such component is histamine, which is present in red wines to a much higher degree than in white wine, and is a potent mediator of allergic responses. 10 Although ingested histamine has been shown to play a role in intolerance and asthmatic reactions to wines in susceptible individuals, 10,11 the extent of this is not clear. Whether histamine played a role in this specific patient is not known; however, the kinetics of this reaction suggests otherwise. Plasma levels of histamine in intolerant individuals have been found to peak between 20 minutes and 30 minutes after a challenge and therefore symptoms initiated by this mediator would be expected to follow a similar time course. 11 Studies of

5 J ALLERGY CLIN IMMUNOL VOLUME 103, NUMBER 1, PART 1 Vally et al 45 FIG 4. Response of subject 15 to high-sulfite wine challenge (filled boxes) and to repeat low-sulfite wine challenges, challenge 1 (open boxes) and challenge 2 (open triangles). FIG 5. Responsiveness of 3 subjects to specific problem wines: subject 1 (filled triangles), subject 8 (open boxes), subject 15 (filled boxes), and the average change in FEV 1 in response to control challenges, n = 3 (*). Baseline FEV 1 represented by horizontal dashed line. TABLE II. Mean maximal fall in FEV 1, FEF 25-75, and PEF in response to wine challenge Red wine (%) Red placebo (%) White wine (%) White placebo (%) FEV (± 2.4) 3.82 (± 1.5) 2.96 (± 1.6) 3.00 (± 1.5) FEF (± 5.1) (± 3.3) 9.66 (± 4.8) 7.78 (± 3.9) PEF 8.12 (± 2.2) 5.12 (± 1.9) 3.31 (± 2.1) 3.78 (± 1.7) Means are expressed as a percentage of baseline values (± SEM). other components in wines capable of inducing asthmatic reactions must be pursued. 3 The overall lack of reactivity to low-sulfite wine challenges suggested that the sulfites might be playing a major role in the asthmatic responses to wines reported by subjects in this study. However, we were unable to demonstrate this, because only 2 individuals exhibited asthmatic reactions to high-sulfite wine challenge. In contrast, Dahl et al 6 suggested sulfites were playing a role in the reactions of 9 of 18 red wine sensitive subjects with asthma who were challenged. This finding is surprising because white wines usually have much higher sulfite concentrations than red wines and therefore suggests other components in red wines may have been potentiating the responses to the sulfites in these individuals. In the study by Dahl et al, 6 no difference was seen in the responsiveness of individuals to low-sulfite red wines (total sulfur dioxide concentration, 50 to 55 ppm) with differing amine levels. However, the only high-sulfite wine challenge to be undertaken (total sulfur dioxide concentration, 265 to 275 ppm) was also extremely high in amine content (8.5 to 9.5 mg/l). Therefore the possible role of biogenic amines in potentiating high-sulfite red wine responses is not clear. Significantly, we challenged subjects with white wines, which differ chemically from red wines and generally have a much lower amine concentration, 10 which may explain the smaller number of sulfite reactors found in our study. However, whether other agents are capable of potentiating responses to the sulfites in wines, 12 or alternatively, whether other factors influence individual s reactivity to the sulfites in wines 13 is not clear. Importantly, the 2 positive responses to high-sulfite wines in this study were marked and rapid, indicating an exquisite sensitivity in some individuals to the sulfites present in wines. The most intriguing aspect of the present study was the number of individuals who, despite clear histories of wine sensitivity, remained unresponsive to a challenge. Of the 10 individuals challenged with placebo, low-sulfite wines, and high-sulfite wines, 7 individuals remained unresponsive. A similar result was obtained by Dahl et al 6 with 9 of 18 subjects not responding to a challenge with a series of modified red wines despite a clear clinical history. The reasons for the lack of reactivity to formal challenge in both our study and that of Dahl et al 6 suggest that other factors may be playing an important role in these reactions. Some individuals may react to wines only when their asthma is unstable. Dahl et al 6 described pollen-sensitive asthmatics who only reacted to red wines in the pollen season, when presumably their asthma was less stable. In this study, one subject exhibited a positive response to the high-sulfite wine challenge at a time when both clinical interview and baseline lung function measurements indicated that there had been a change in asthma severity. A low-sulfite wine challenge at this stage was also positive, despite a previous low-sulfite challenge being negative. Therefore baseline asthma severity seems to have influenced the reactivity of this individual to low-sulfite white wine. Anecdotally, many

6 46 Vally et al J ALLERGY CLIN IMMUNOL JANUARY 1999 subjects described more noticeable reactions to wine when their asthma symptoms were less stable, and conversely, being able to tolerate wines on occasions when their asthma was well controlled. Because strict criteria regarding asthma severity and stability were required to enter this study, it is possible this may have contributed to the overall paucity of positive responses to challenge. Importantly, baseline asthma severity did not seem to influence reactivity to the sulfites, which was supported by the 2 sulfite responders exhibiting a baseline FEV 1 greater than 100% of predicted value. 14,15 Environmental cofactors may also play a role in asthmatic reactions to wines. That is, drinking wine may potentiate asthmatic responses to cigarette smoke or other irritants or vice versa. Blinded challenges in 3 of our subjects with specific wines to which they had previously reacted to failed to precipitate a significant fall in lung function when challenged with these same wines in a clinical setting (Fig 5). In subjects 1 and 8, specific white wine triggers failed to stimulate a change in lung function or in subjective measures of worsening asthma. In subject 15, the challenge with a specific red wine trigger caused a nonsignificant fall in the FEV 1 ( 13.5%), and difficulty in breathing was observed, but this was not to the same degree as had previously been experienced with this particular wine. Increases in bronchial hyper-reactivity after exposure to food or food chemicals have been reported by various investigators However, whether wine exposure results in increased bronchial reactivity is unknown. In trying to explain the number of nonreactors, it is important to note that a number of individuals reported changes in their asthma symptoms in response to a challenge that were not reflected in lung function measurements. This may indicate that spirometric measurement alone may not be sensitive enough to pick up reactions to wines in all individuals. 19 Only 2 individuals responded to placebo wine in this study, suggesting that a psychologic or nonspecific mechanism of reactivity is unlikely to explain the large number of patients who report sensitivity to wines. The results of this study highlight the complex nature of wine-induced asthma. We were able to demonstrate reactivity in 2 individuals to the sulfites in white wine, with one of these individuals also reacting to a specific component present only in the low-sulfite red wine. Two individuals exhibited reactions to placebo wine challenges, suggesting either a nonspecific or psychologic component to their reactions. One individual exhibited an inconsistent response to low-sulfite white wine, which seemed related to asthma severity at the time of challenge. Most intriguing, however, was that, from a cohort of selfreported wine-sensitive individuals with asthma, 7 of 10 subjects who were challenged with both low- and highsulfite wines did not demonstrate a reaction to any of the challenges delivered. Whether this lack of reactivity to a formal challenge is indicative of cofactors that play an important role in these reactions (eg, unstable asthma or environmental triggers, such as cigarette smoke or other allergens) or whether patient histories are unreliable is unclear at this stage and requires further investigation. The authors thank BRL Hardy Wine Co. for the donation of the preservative-free wines used in this study, and Christian Hansen Pty. Ltd. for supplying the food coloring used in the making of placebo wines. REFERENCES 1. Ayres J, Clarke TJH. Alcoholic drinks and asthma: a survey. 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