No correlation between wine intolerance and histamine content of wine

Alcohol-Induced Headache with Neuroinflammation: Recent Progress

Ethanol and other congeners in alcoholic beverages and foods are known triggers of alcohol-induced headaches (AIHs). Recent studies implicate AIHs as an important underlying factor for neuroinflammation. Studies show the relationship between alcoholic beverages, AIH agents, neuroinflammation, and the pathway they elicit. However, studies elucidating specific AIH agents’ pathways are scarce. Works reviewing their pathways can give invaluable insights into specific substances’ patterns and how they can be controlled. Hence, we reviewed the current understanding of how AIH agents in alcoholic beverages affect neuroinflammation and their specific roles. Ethanol upregulates transient receptor potential cation channel subfamily V member 1 (TRPV1) and Toll-like receptor 4 (TLR4) expression levels; both receptors trigger a neuroinflammation response that promotes AIH manifestation—the most common cause of AIHs. Other congeners such as histamine, 5-HT, and condensed tannins also upregulate TRPV1 and TLR4, neuroinflammatory conditions, and AIHs. Data elucidating AIH agents, associating pathways, and fermentation parameters can help reduce or eliminate AIH inducers and create healthier beverages.

Dual-recognition molecularly imprinted aptasensor based on gold nanoparticles decorated carboxylated carbon nanotubes for highly selective and sensitive determination of histamine in different matrices

In this study, an electrochemical aptamer based sensor (aptasensor) was proposed for specific recognition of histamine (HIS). The electrochemical aptasensor based on fabrication of glassy carbon electrode (GCE) with molecular imprinted polymer (MIP) and DNA aptamers on gold nanoparticles (AuNPs) and carboxylated carbon nanotubes (cCNTs) (MIP-apta/AuNPs/cCNTs/GCE). The aptasensor exhibits high selectivity towards HIS detection as it has two recognition elements which are MIP cavities and aptamer interaction. Upon exposure of MIP-apt/AuNPs/cCNTs/GCE to HIS, the current of redox probe was decreased that depends on the template (HIS) concentration. The effects of aptamer concentration, incubation time, pH and AuNPs electro-deposition time were optimized. Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were used to analyze HIS in complicated matrices. Favorable performance of MIP-apt/AuNPs/cCNTs/GCE was achieved with linearity ranges of 0.46-35 nmol L^-1 and 0.35-35 nmol L^-1 with limits of detection (LODs, S/N = 3) of 0.15 nmol L^-1 and 0.11 nmol L^-1 using DPV and EIS, respectively. The fabricated aptasensor displayed high selectivity, desirable reproducibility and stability. The MIP-apt/AuNPs/cCNTs/GCE was used to detect HIS in human plasma and canned tuna samples with good recoveries % and RSDs %.

An Overview on Biogenic Amines in Wine

Biogenic amines (BAs) are low molecular weight compounds formed from precursor amino acids, mainly by microbial decarboxylation. The presence of these compounds is important in the food and beverage industry because, in high amounts, they can lead to negative effects on consumers. In this review, we illustrate the critical aspects needed to control the formation of BAs during winemaking and their presence in the final product. Recent biotechnological approaches related to microorganisms and their ability to reduce BAs are illustrated. The current methods used for BA detection and quantification are also presented. These methods are very important to consider, as BAs can serve as markers for the quality assessment of products. The information presented here offers an overview useful for identifying specific parameters and conditions which should be controlled to minimise BA content in wine; knowledge about BAs in foods and beverages has been accumulating in recent years, not only to ensure and improve quality (since BAs have been used as an indicator of spoilage) but especially to guarantee consumer safety due to the potential toxic effects of BAs on humans.

Combined Use of S. pombe and L. thermotolerans in Winemaking. Beneficial Effects Determined Through the Study of Wines' Analytical Characteristics

The most common way to produce red wine is through the use of Saccharomyces cerevisiae strains for alcoholic fermentation and lactic acid bacteria for malolactic fermentation. This traditional winemaking methodology produces microbiologically stable red wines. However, under specific conditions off-flavours can occur, wine quality can suffer and human health problems are possible, especially after the second fermentation by the lactic acid bacteria. In warm countries, problems during the malolactic fermentation arise because of the high pH of the must, which makes it very difficult to properly control the process. Under such conditions, wines with high acetic acid and histamine concentrations are commonly produced. This study investigates a recent red wine-making technology that uses a combination of Lachancea thermotolerans and Schizosaccharomyces pombe as an alternative to the conventional malolactic fermentation. This work studies new parameters such as aroma compounds, amino acids, ethanol index and sensory evaluation. Schizosaccharomyces pombe totally consumes malic acid while Lachancea thermotolerans produces lactic acid, avoiding excessive deacidification of musts with low acidity in warm viticulture areas. This methodology also reduces the malolactic fermentation hazards in wines with low acidity. The main products are wines that contain less acetic acid, less biogenic amines and precursors and less ethyl carbamate precursors than the traditional wines produced via conventional fermentation techniques.

Selected Schizosaccharomyces pombe Strains Have Characteristics That Are Beneficial for Winemaking

At present, wine is generally produced using Saccharomyces yeast followed by Oenococus bacteria to complete malolactic fermentation. This method has some unsolved problems, such as the management of highly acidic musts and the production of potentially toxic products including biogenic amines and ethyl carbamate. Here we explore the potential of the fission yeast Schizosaccharomyces pombe to solve these problems. We characterise an extensive worldwide collection of S. pombe strains according to classic biochemical parameters of oenological interest. We identify three genetically different S. pombe strains that appear suitable for winemaking. These strains compare favourably to standard Saccharomyces cerevisiae winemaking strains, in that they perform effective malic acid deacidification and significantly reduce levels of biogenic amines and ethyl carbamate precursors without the need for any secondary bacterial malolactic fermentation. These findings indicate that the use of certain S. pombe strains could be advantageous for winemaking in regions where malic acid is problematic, and these strains also show superior performance with respect to food safety.

Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence

Although there is considerable literature pertaining to IgE and non IgE-mediated food allergy, there is a paucity of information on non-immune mediated reactions to foods, other than metabolic disorders such as lactose intolerance. Food additives and naturally occurring 'food chemicals' have long been reported as having the potential to provoke symptoms in those who are more sensitive to their effects. Diets low in 'food chemicals' gained prominence in the 1970s and 1980s, and their popularity remains, although the evidence of their efficacy is very limited. This review focuses on the available evidence for the role and likely adverse effects of both added and natural 'food chemicals' including benzoate, sulphite, monosodium glutamate, vaso-active or biogenic amines and salicylate. Studies assessing the efficacy of the restriction of these substances in the diet have mainly been undertaken in adults, but the paper will also touch on the use of such diets in children. The difficulty of reviewing the available evidence is that few of the studies have been controlled and, for many, considerable time has elapsed since their publication. Meanwhile dietary patterns and habits have changed hugely in the interim, so the conclusions may not be relevant for our current dietary norms. The conclusion of the review is that there may be some benefit in the removal of an additive or a group of foods high in natural food chemicals from the diet for a limited period for certain individuals, providing the diagnostic pathway is followed and the foods are reintroduced back into the diet to assess for the efficacy of removal. However diets involving the removal of multiple additives and food chemicals have the very great potential to lead to nutritional deficiency especially in the paediatric population. Any dietary intervention, whether for the purposes of diagnosis or management of food allergy or food intolerance, should be adapted to the individual's dietary habits and a suitably trained dietitian should ensure nutritional needs are met. Ultimately a healthy diet should be the aim for all patients presenting in the allergy clinic.

[Debating histamine intolerance: are adverse reactions to histamine-containing foods fact or fiction?]

Low-histamine diets are very popular and often self-imposed among people suspecting histamine intolerance. Most of these diets avoid a huge variety of foods containing more or less histamine, which has a considerable impact on their quality of life, but in most cases no long-term benefit. Underlying a diminished capacity for histamine degradation, the lack of partial or complete symptom improvement might be due to the fact that endogenous histamine release could also be responsible for symptoms. The role of ingested histamine-below the level for intoxication-is discussed controversially. However, it is obvious that the histamine content of a certain food alone is not enough to predict its tolerance. If histamine intolerance is suspected, an individual diagnostic and therapeutic procedure is mandatory in order to minimize avoidance and to preserve a high quality of life. Ideally this is done in a close cooperation between allergists and nutritionists.

Association between loss-of-function mutations in the filaggrin gene and self-reported food allergy and alcohol sensitivity

BACKGROUND

Loss-of-function mutations of the filaggrin (FLG) gene cause an impaired skin barrier and increase the risk of atopic dermatitis. Interestingly, FLG mutations have also been found to be associated with a high risk of peanut allergy.

OBJECTIVE

We investigated the association of FLG mutations with self-reported food allergy, symptoms of oral allergy syndrome (OAS), and alcohol sensitivity.

METHODS

A total of 3,471 adults from the general population participated in a health examination. Information on food allergies, OAS and alcohol sensitivity was obtained by questionnaire. FLG mutation carriers were defined as having at least one null mutation allele of R501X or 2282del4. Primary lactose intolerance (PLI) was defined as the C/C genotype of the rs4988235 polymorphism.

RESULTS

FLG mutations were associated with a higher risk of self-reported allergy to eggs (OR 3.22 and 95% CI 1.46-7.11), milk (OR 2.10 and 95% CI 1.12-3.92), fish (OR 4.54 and 95% CI 1.88-10.96) and wheat (OR 3.59 and 95% CI 1.61-8.02), but not with symptoms of OAS (OR 1.05 and 95% CI 0.73-1.51). Serum-specific IgE was measured in a subsample and confirmed the association between FLG and IgE to milk. A significant gene-by-gene interaction between FLG and PLI was observed in relation to self-reported allergy to milk. Furthermore, FLG mutations were associated with a higher risk of alcohol sensitivity.

CONCLUSIONS

We found that loss-of-function mutations in the FLG gene were significantly associated with self-reported food allergy and alcohol sensitivity, but not with OAS. These findings, if confirmed, support the idea that skin barrier functions may be involved in the pathogenesis of food allergy.

Histamine intolerance: lack of reproducibility of single symptoms by oral provocation with histamine: a randomised, double-blind, placebo-controlled cross-over study

OBJECTIVES

The term histamine intolerance stands for a range of symptoms involving various effector organs after the consumption of histamine-rich food. Our intention was to objectify and quantify histamine-associated symptoms and to analyse whether oral administration of the histamine-degrading enzyme diamine oxidase (DAO) caused a reduction of symptoms.

PATIENTS AND METHODS

Four Austrian centres participated. Patients suspected to be histamine intolerant were recruited. The first step consisted in the open oral provocation of these patients with 75 mg of liquid histamine. Patients who developed symptoms were tested in a randomised double blind crossover provocation protocol using histamine-containing and histamine-free tea in combination with DAO capsules or placebo. Main and secondary symptoms (strongest and weaker symptoms based on a ten-point scale) were defined, the grand total of all symptoms of the individual provocation steps was determined and changes in symptoms after administration of DAO were measured.

RESULTS

Thirty nine patients reacted to the open histamine provocation and were enrolled in the blinded part. Here, both the main and secondary symptoms were not reproducible. Subjects reacted sometimes unexpectedly and randomly. Regarding the total symptom scores, the differences between the three treatment groups were statistically significant. The intake of DAO demonstrated a statistically significant reduction of histamine-associated symptoms compared to placebo (P = 0.014).

CONCLUSIONS

Oral provocation with 75 mg of liquid histamine failed to reproduce histamine-associated single symptoms in many patients. One may suggest that histamine-intolerant subjects reacted with different organs on different occasions. As a consequence, reproducibility of single symptoms alone may not be appropriate to diagnose histamine-intolerance whereas a global symptom score could be more appropriate. The fact, that the intake of DAO capsules compared to placebo led to a statistically significant reduction of total symptom scores, may indirectly point in the same direction.

Genetic determinants of both ethanol and acetaldehyde metabolism influence alcohol hypersensitivity and drinking behaviour among Scandinavians

BACKGROUND

Although hypersensitivity reactions following intake of alcoholic drinks are common in Caucasians, the underlying mechanisms and clinical significance are not known. In contrast, in Asians, alcohol-induced asthma and flushing have been shown to be because of a single nucleotide polymorphism (SNP), the acetaldehyde dehydrogenase 2 (ALDH2) 487lys, causing decreased acetaldehyde (the metabolite of ethanol) metabolism and high levels of histamine. However, the ALDH2 487lys is absent in Caucasians.

OBJECTIVES

To investigate the genetic determinants of self-reported alcohol-induced hypersensitivity reactions in Caucasians.

METHODS

The study included two population-based studies of 1216 and 6784 adults living in Copenhagen. Assessment of alcohol consumption and hypersensitivity reactions (in a subgroup) was performed by a questionnaire and was related to common SNPs of genes encoding alcohol dehydrogenases (ADHs) and ALDHs.

RESULTS

In both populations, alcohol drinkers with a genetically determined fast metabolism of ethanol (the A allele of the ADH1b rs1229984) had an increased risk of alcohol-induced hypersensitivity reactions (odds ratio AA/AG vs. GG in combined populations: 1.82, 95% CI 1.04-3.17). In both populations, a common SNP encoding ALDH1b1 (rs2228093) was found to be significantly associated with alcohol-induced hypersensitivity (odds ratio TT vs. CC in combined populations: 2.53, 95% CI 1.31-4.90).

CONCLUSIONS

Our data support that alcohol sensitivity in Caucasians is genetically determined and suggest that a histamine-releasing effect of acetaldehyde represents a plausible biological mechanism. Furthermore, we present the first report of a clinically significant SNP within the acetaldehyde-metabolizing system in a Caucasian population.

Prevalence of self-reported hypersensitivity symptoms following intake of alcoholic drinks

BACKGROUND; Although hypersensitivity symptoms following alcoholic drink consumption are common in asthmatics, the prevalence of such symptoms in the general population is not known.

OBJECTIVE

To assess the prevalence of hypersensitivity symptoms following alcoholic drink consumption in an adult Northern European general population and the association of these symptoms with the prevalence of allergic rhinitis (AR) and asthma.

METHODS

In 2006, a postal questionnaire was sent to a random sample of 18-69-year-olds living in Copenhagen, the capital of Denmark. The response rate was 70.7% (4242/6000).

RESULTS

The prevalence of alcohol-induced symptoms from the upper airways, lower airways, and skin was 7.6% [95% confidence interval (CI): 6.8-8.4%], 3.2% (95% CI: 2.7-3.8%), and 7.2% (95% CI: 6.4-8.9%), respectively. A total of 13.9% (95% CI: 12.9-15.0%) had ever experienced alcohol-induced symptoms from at least one of the three regions (upper airways, lower airways, or skin), and 9.9% (95% CI: 9.0-10.8%) had experienced symptoms in the last 12 months. All types of beverages were commonly reported as triggers of hypersensitivity symptoms, red wine being the most common. Alcohol-induced hypersensitivity symptoms from the upper and lower airways were significantly more prevalent in persons with AR and asthma (odds ratios between 3.0 and 8.1, P-value <0.001 for all associations).

CONCLUSIONS

In this Northern European general population, self-reported hypersensitivity symptoms following the intake of alcoholic drinks are common. These symptoms were markedly more prevalent in persons with AR and asthma. The underlying mechanisms and the clinical significance of these symptoms remain to be elucidated.

Histamine and histamine intolerance

Histamine intolerance results from a disequilibrium of accumulated histamine and the capacity for histamine degradation. Histamine is a biogenic amine that occurs to various degrees in many foods. In healthy persons, dietary histamine can be rapidly detoxified by amine oxidases, whereas persons with low amine oxidase activity are at risk of histamine toxicity. Diamine oxidase (DAO) is the main enzyme for the metabolism of ingested histamine. It has been proposed that DAO, when functioning as a secretory protein, may be responsible for scavenging extracellular histamine after mediator release. Conversely, histamine N-methyltransferase, the other important enzyme inactivating histamine, is a cytosolic protein that can convert histamine only in the intracellular space of cells. An impaired histamine degradation based on reduced DAO activity and the resulting histamine excess may cause numerous symptoms mimicking an allergic reaction. The ingestion of histamine-rich food or of alcohol or drugs that release histamine or block DAO may provoke diarrhea, headache, rhinoconjunctival symptoms, asthma, hypotension, arrhythmia, urticaria, pruritus, flushing, and other conditions in patients with histamine intolerance. Symptoms can be reduced by a histamine-free diet or be eliminated by antihistamines. However, because of the multifaceted nature of the symptoms, the existence of histamine intolerance has been underestimated, and further studies based on double-blind, placebo-controlled provocations are needed. In patients in whom the abovementioned symptoms are triggered by the corresponding substances and who have a negative diagnosis of allergy or internal disorders, histamine intolerance should be considered as an underlying pathomechanism.

Potential food allergens in wine: Double-blind, placebo-controlled trial and basophil activation analysis

OBJECTIVE

Recent Australian and international legislation requires labeling of wines made by using the potentially allergenic food proteins casein, milk, egg white, or isinglass (fish-derived) where "there is a detectable residual processing aid." We investigated whether wines fined using these proteins or non-grape-derived tannins (tree-nut derived) can provoke significant clinical allergic reactions (anaphylaxis) in patients with confirmed immunoglobulin E-mediated relevant food allergy.

METHODS

A double-blind, placebo-controlled trial was performed to determine whether allergic reactions followed consumption of Australian commercial wines fined using one or more of the legislation-targeted food proteins. In addition, allergenicity of a larger panel of these wines was evaluated by blood basophil activation.

RESULTS

No anaphylaxis was induced by wine consumption. Three mild clinical reactions to protein-fined wine and two mild reactions to unfined wine occurred, but there was no statistically significant difference in reaction parameters between subject groups or between processing aids. No pattern of basophil activation correlated with wine type, processing aid, or subject group.

CONCLUSION

Wines fined with egg white, isinglass, or non-grape-derived tannins present an extremely low risk of anaphylaxis to fish-, egg-, or peanut-allergic consumers. Although consumption of milk protein-fined wine did not induce anaphylaxis, there were insufficient subjects to determine statistically whether wines fined with milk proteins present a risk to the very rare milk-allergic consumers. In summary, the observed lack of anaphylaxis and basophil activation induced by wines made using the legislation-targeted food proteins according to good manufacturing practice suggests negligible residual food allergens in these wines.

Alcohol-induced upper airway symptoms: prevalence and co-morbidity

Little is known about effects of alcohol intake on the upper, nasal airways. The present aim was to examine the prevalence of alcohol-induced nasal symptoms (ANS) and to explore associations between ANS and other respiratory diseases. A postal questionnaire focused on respiratory diseases and symptoms was sent to 11,933 randomly selected adult individuals. Subjects with ANS, n = 316 (3.4%) received a second questionnaire focusing on this condition. Nine thousand three hundred and sixteen (78%) subjects answered the first and 228 (72%) the second questionnaire. Two-thirds of the subjects with ANS were women. Red wine and white wine were the most frequent triggers of ANS, reported by 83% and 31% of the subjects, respectively. Nasal blockage was the most prominent symptom, but also sneezing, nasal discharge, as well as lower airway symptoms occurred after intake of alcoholic drinks. Self-reported physician's diagnoses of asthma, chronic bronchitis/emphysema, chronic obstructive pulmonary disease (COPD), as well as allergic rhinitis were more common in subjects with ANS compared with the general population (P < 0.001 for all comparisons). In conclusion, ANS are common and are about twice as frequent in women than in men. ANS seem to be associated with important respiratory diseases such as asthma, chronic bronchitis, COPD, and allergic rhinitis.

Acetaldehyde induces histamine release from human airway mast cells to cause bronchoconstriction

BACKGROUND

Approximately half of the Japanese asthmatics experience exacerbation of asthma after alcohol consumption. We previously reported that this phenomenon is probably caused by histamine release from mast cells by acetaldehyde stimulation. However, no reports have described the effects of acetaldehyde on human airway mast cells. The purpose of the present study was to demonstrate acetaldehyde-induced histamine release from human airway mast cells with subsequent airway smooth muscle contraction and to investigate the ensuing mechanisms.

METHODS

Human tissue samples were prepared from the lungs resected from patients with lung cancer. The effect of acetaldehyde on airway muscle tone and the concentration of chemical mediators released in the organ bath were measured before and after acetaldehyde stimulation. Mast cells were prepared from lung parenchyma by the immunomagnetic method and then stimulated with acetaldehyde to determine the chemical mediators released.

RESULTS

Acetaldehyde (>3 x 10(-4) M) increased airway muscle tone, which was associated with a significant increase in the release of histamine, but not thromboxane B2 or cysteinyl-leukotrienes. A histamine (H1 receptor) antagonist completely inhibited acetaldehyde-induced bronchial smooth muscle contraction. Acetaldehyde also induced a significant histamine release from human lung mast cells and degranulation of mast cells.

CONCLUSIONS

The present results strongly suggest that acetaldehyde stimulates human airway mast cells to release histamine, which may be involved in bronchial smooth muscle contraction following alcohol consumption.

Intolerance to dietary biogenic amines: a review

OBJECTIVE

To evaluate the scientific evidence for purported intolerance to dietary biogenic amines.

DATA SOURCES

MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature.

STUDY SELECTION

Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive.

RESULTS

A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache.

CONCLUSIONS

The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

Allergic and asthmatic reactions to alcoholic drinks

Alcoholic drinks are capable of triggering a wide range of allergic and allergic-like responses, including rhinitis, itching, facial swelling, headache, cough and asthma. Limited epidemiological data suggests that many individuals are affected and that sensitivities occur to a variety of drinks, including wine, beer and spirits. In surveys of asthmatics, over 40% reported the triggering of allergic or allergic-like symptoms following alcoholic drink consumption and 30 - 35% reported worsening of their asthma. Sensitivity to ethanol itself can play a role in triggering adverse responses, particularly in Asians, which is due mainly to a reduced capacity to metabolize acetaldehyde. In Caucasians, specific non-alcohol components are the main cause of sensitivities to alcoholic drinks. Allergic sensitivities to specific components of beer, spirits and distilled liquors have been described. Wine is clearly the most commonly reported trigger for adverse responses. Sensitivities to wine appear to be due mainly to pharmacological intolerances to specific components, such as biogenic amines and the sulphite additives. Histamine in wine has been associated with the triggering of a wide spectrum of adverse symptoms, including sneezing, rhinitis, itching, flushing, headache and asthma. The sulphite additives in wine have been associated with triggering asthmatic responses. Clinical studies have confirmed sensitivities to the sulphites in wine in limited numbers of individuals, but the extent to which the sulphites contribute to wine sensitivity overall is not clear. The aetiology of wine-induced asthmatic responses may be complex and may involve several co-factors.

The relationship of alcohol consumption to total immunoglobulin E and the development of immunoglobulin E sensitization: the Copenhagen Allergy Study

BACKGROUND

Several studies in patient populations have reported a positive association between alcohol consumption and serum total IgE. Furthermore, we have previously reported a positive association between alcohol consumption and the prevalence of skin prick test (SPT positivity) to inhalant allergens in a population-based cross-sectional study.

OBJECTIVE

To investigate the relationship of alcohol consumption to levels of serum total IgE and the development of IgE sensitization to inhalant allergens.

METHODS

In 1990, self-reported consumption of alcohol, serum total IgE, SPT positivity and specific IgE positivity to inhalant allergens were assessed in 1112 subjects, aged 15-69 years, participating in a population-based cross-sectional study in Copenhagen, Denmark. In 1998, they were invited to a follow-up and 734 were re-examined (participation rate 69.0%). Adjustment for potential confounders was performed by using multivariable regression analyses.

RESULTS

In non-atopic (specific IgE negative) subjects there was a positive association between alcohol consumption and the concentration of total IgE (P = 0.001). During the follow-up period, 45 and 33 subjects developed SPT positivity and specific IgE positivity, respectively. There was no significant association between alcohol consumption and the development of SPT positivity or specific IgE positivity. However, the risk of developing SPT positivity tended to increase with increasing consumption of alcohol (P = 0.055).

CONCLUSIONS

This epidemiological study confirms that alcohol consumption has an influence on levels of serum total IgE. A significant association between alcohol consumption and the development of IgE sensitization was not established. However, there seems to be a lack epidemiological data on this issue.

Ethanol as a cause of hypersensitivity reactions to alcoholic beverages

BACKGROUND

Adverse reactions after ingestion of alcoholic beverages are common. Metabolic differences in individuals and also the histamine content in alcoholic beverages have been implicated. By contrast pure ethanol has rarely been reported as a cause of hypersensitivity reactions and its mechanism has not been clarified yet.

OBJECTIVE

To determine whether ethanol itself accounts for alcohol hypersensitivity in patients with anaphylactic reactions after alcohol intake. In search of possible pathomechanisms all patients were analysed by skin prick testing and sulfidoleukotriene production of peripheral leucocytes using ethanol and its metabolites.

METHODS

Double-blind, placebo-controlled food challenges with a cumulated amount of 30 mL ethanol were performed in 12 adult patients with a positive history of adverse reactions after consumption of different alcoholic beverages. Skin prick tests and measurement of sulfidoleukotriene production were performed using different concentrations of ethanol and acetaldehyde from 50 to 1000 mm.

RESULTS

Oral challenges with pure ethanol were positive in six out of eleven patients. All challenge-positive patients, but also four out of five challenge-negative patients, showed an increased sulfidoleukotriene production in-vitro compared with healthy controls. Skin prick tests using alcoholic beverages, ethanol, acetaldehyde and acetic acid were negative in all patients (12/12).

CONCLUSION

Our study shows that ethanol itself is a common causative factor in hypersensitivity reactions to alcoholic beverages. These reactions occur dose-dependent and a non-IgE-mediated pathomechanism is likely, because skin prick tests were negative in all cases. Increased sulfidoleukotriene production was determined in some patients, but is no reliable predictor. Therefore oral provocation tests remain indispensable in making the diagnosis of ethanol hypersensitivity.

Late-onset allergy-like reactions to X-ray contrast media

PURPOSE OF REVIEW

The purpose of the present review is to describe recent insight into the pathomechanism of the late-onset allergy-like reactions which affect 2-3% of contrast medium-exposed patients, and to give advice regarding prophylactic measures to avoid recurrence of such reactions.

RECENT FINDINGS

It is well recognized that the majority of contrast media-induced late-onset reactions are cutaneous reactions of the maculopapular, urticarial and angioedema types, with occasional occurrence of more serious, bullous eruptions. Recent findings strongly indicate that these reactions are T cell-mediated. The current evidences for this concept are the described clinical symptoms; the high incidence of reactions in interleukin-2-treated patients; the positive results from skin, provocation and lymphocyte transformation testing of affected patients; and the histopathology of skin eruptions and positive skin test sites.

SUMMARY

On the basis of this new knowledge, several prophylactic measures are proposed to avoid repeat reactions in patients with previous late-onset contrast medium reactions. All persons receiving contrast media should be informed that transient skin reactions may develop up to 7 days after contrast medium exposure. Those who experience such reactions should be advised to see an allergist for diagnosis of the reaction. Skin testing with a panel of different contrast media appears to be useful for confirming the presence of an allergic reaction and for identifying alternative contrast media that can be safely used. For undiagnosed persons, a contrast medium that is structurally different from the product that precipitated the reaction should be chosen if re-exposure to contrast media is required. Pretreatment with corticosteroids may also be tried, although its protective effect has not been systematically studied.

Aromatic components of food as novel eliciting factors of pseudoallergic reactions in chronic urticaria

BACKGROUND

Pseudoallergic reactions (PARs) against both additives and natural foods have been reported to elicit chronic urticaria, but in natural food the responsible ingredients are largely unknown.

OBJECTIVE

The study was aimed at identifying novel pseudoallergens in food and focused on evaluating tomatoes, white wine, and herbs as frequently reported food items eliciting wheal responses in urticaria.

METHODS

In 33 patients with chronic urticaria and PARs to food (proved by means of elimination diet and subsequent re-exposure with provocation meals), oral provocation tests were performed with field-grown tomatoes, organically grown white wine (whole food, steam distillates, and residues), oily extracts from herbs, and food additives. In addition, skin biopsy specimens from patients were studied for in vitro mast-cell histamine release with tomato distillate alone or on subsequent stimulation with anti-IgE, substance P, and C5a.

RESULTS

Seventy-six percent of patients reacted to whole tomato (steam distillate, 45%; residue, 15%), 50% to food additives, 47% to herbs, and 44% to whole wine (extract, 27%; residue, 0%). Histamine, protein, and high levels of salicylate were only found in residues. The tomato distillate was further analyzed by means of mass spectroscopy, identifying low molecular-weight aldehydes, ketones, and alcohol as major ingredients. In vitro histamine release was not caused by tomato extract itself but was enhanced by means of subsequent stimulation with substance P and C5a but not by anti-IgE.

CONCLUSION

Aromatic volatile ingredients in food are novel agents eliciting PARs in chronic urticaria. Histamine, salicylate, and a direct mast-cell histamine release are not involved in this reactivity to naturally occurring pseudoallergens.