Positive skin tests and Prausnitz-Küstner reactions in metabisulfite-sensitive subjects

Proposal of 0.5 mg of protein/100 g of processed food as threshold for voluntary declaration of food allergen traces in processed food-A first step in an initiative to better inform patients and avoid fatal allergic reactions: A GA²LEN position paper

BACKGROUND

Food anaphylaxis is commonly elicited by unintentional ingestion of foods containing the allergen above the tolerance threshold level of the individual. While labeling the 14 main allergens used as ingredients in food products is mandatory in the EU, there is no legal definition of declaring potential contaminants. Precautionary allergen labeling such as "may contain traces of" is often used. However, this is unsatisfactory for consumers as they get no information if the contamination is below their personal threshold. In discussions with the food industry and technologists, it was suggested to use a voluntary declaration indicating that all declared contaminants are below a threshold of 0.5 mg protein per 100 g of food. This concentration is known to be below the threshold of most patients, and it can be technically guaranteed in most food production. However, it was also important to assess that in case of accidental ingestion of contaminants below this threshold by highly allergic patients, no fatal anaphylactic reaction could occur. Therefore, we performed a systematic review to assess whether a fatal reaction to 5mg of protein or less has been reported, assuming that a maximum portion size of 1kg of a processed food exceeds any meal and thus gives a sufficient safety margin.

METHODS

MEDLINE and EMBASE were searched until 24 January 2021 for provocation studies and case reports in which one of the 14 major food allergens was reported to elicit fatal or life-threatening anaphylactic reactions and assessed if these occurred below the ingestion of 5mg of protein. A Delphi process was performed to obtain an expert consensus on the results.

RESULTS

In the 210 studies included, in our search, no reports of fatal anaphylactic reactions reported below 5 mg protein ingested were identified. However, in provocation studies and case reports, severe reactions below 5 mg were reported for the following allergens: eggs, fish, lupin, milk, nuts, peanuts, soy, and sesame seeds.

CONCLUSION

Based on the literature studied for this review, it can be stated that cross-contamination of the 14 major food allergens below 0.5 mg/100 g is likely not to endanger most food allergic patients when a standard portion of food is consumed. We propose to use the statement "this product contains the named allergens in the list of ingredients, it may contain traces of other contaminations (to be named, e.g. nut) at concentrations less than 0.5 mg per 100 g of this product" for a voluntary declaration on processed food packages. This level of avoidance of cross-contaminations can be achieved technically for most processed foods, and the statement would be a clear and helpful message to the consumers. However, it is clearly acknowledged that a voluntary declaration is only a first step to a legally binding solution. For this, further research on threshold levels is encouraged.

Adverse reactions to food additives

Food additives are naturally occurring or synthetic substances that are added to food to modify the color, taste, texture, stability, or other characteristics of foods. These additives are ubiquitous in the food that we consume on a daily basis and, therefore, have been the subject of much scrutiny about possible reactions. Despite these concerns, the overall prevalence of food additive reactions is 1-2%, with a minority of the wide variety of symptoms attributed to food-additive exposure being reproduced by double-blind placebo controlled challenges. Reactions can be broadly classified into either immunoglobulin E (IgE)- and non-IgE-mediated reactions, with natural additives accounting for most IgE-mediated reactions, and both natural and synthetic additives being implicated in the non-IgE-mediated reactions. Reactions that include asthma exacerbations, urticaria and/or angioedema, or anaphylaxis with ingestion of a food additive are most deserving of further allergy evaluation. In this article, we discussed the different types of adverse reactions that have been described to various food additives. We also reviewed the specifics of how to evaluate and diagnose a food additive allergy in a clinic setting.

Allergy to food additives

PURPOSE OF REVIEW

To provide an update of the studies concerning the diagnosis and management of food additives allergy.

RECENT FINDINGS

Additives improve specific characteristics of food products, but they may induce allergic even life-threatening reactions. Physical examination and medical history are basic to assess specific in-vivo and in-vitro tests. The only treatment for allergic patients consists in avoiding the food containing culprit additives. High-risk patients should be able to recognize severe reactions and self-manage them.

SUMMARY

The prevalence of adverse reactions to food additives is low, and it may depend on comorbidities, like asthma or chronic idiopathic urticaria. Food labels may help the correct identification of ingredients. Natural additives like spices should cause immediate reactions because of a pollen-sensitization or panallargen proteins presence. Additive-free diets may help the patient care, but the authors suggest assessing an oral food challenge with the culprit substance if there are no contraindications.

Final Report on the Safety Assessment of Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite

Sodium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are inorganic salts that function as reducing agents in cosmetic formulations. All except Sodium Metabisulfite also function as hair-waving/straightening agents. In addition, Sodium Sulfite, Potassium Sulfite, Sodium Bisulfite, and Sodium Metabisulfite function as antioxidants. Although Ammonium Sulfite is not in current use, the others are widely used in hair care products. Sulfites that enter mammals via ingestion, inhalation, or injection are metabolized by sulfite oxidase to sulfate. In oral-dose animal toxicity studies, hyperplastic changes in the gastric mucosa were the most common findings at high doses. Ammonium Sulfite aerosol had an acute LC50 of >400 mg/m3 in guinea pigs. A single exposure to low concentrations of a Sodium Sulfite fine aerosol produced dose-related changes in the lung capacity parameters of guinea pigs. A 3-day exposure of rats to a Sodium Sulfite fine aerosol produced mild pulmonary edema and irritation of the tracheal epithelium. Severe epithelial changes were observed in dogs exposed for 290 days to 1 mg/m3 of a Sodium Metabisulfite fine aerosol. These fine aerosols contained fine respirable particle sizes that are not found in cosmetic aerosols or pump sprays. None of the cosmetic product types, however, in which these ingredients are used are aerosolized. Sodium Bisulfite (tested at 38%) and Sodium Metabisulfite (undiluted) were not irritants to rabbits following occlusive exposures. Sodium Metabisulfite (tested at 50%) was irritating to guinea pigs following repeated exposure. In rats, Sodium Sulfite heptahydrate at large doses (up to 3.3 g/kg) produced fetal toxicity but not teratogenicity. Sodium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite were not teratogenic for mice, rats, hamsters, or rabbits at doses up to 160 mg/kg. Generally, Sodium Sulfite, Sodium Metabisulfite, and Potassium Metabisulfite were negative in mutagenicity studies. Sodium Bisulfite produced both positive and negative results. Clinical oral and ocular-exposure studies reported no adverse effects. Sodium Sulfite was not irritating or sensitizing in clinical tests. These ingredients, however, may produce positive reactions in dermatologic patients under patch test. In evaluating the positive genotoxicity data found with Sodium Bisulfite, the equilibrium chemistry of sulfurous acid, sulfur dioxide, bisulfite, sulfite, and metabisulfite was considered. This information, however, suggests that some bisulfite may have been present in genotoxicity tests involving the other ingredients and vice versa. On that basis, the genotoxicity data did not give a clear, consistent picture. In cosmetics, however, the bisulfite form is used at very low concentrations (0.03% to 0.7%) in most products except wave sets. In wave sets, the pH ranges from 8 to 9 where the sulfite form would predominate. Skin penetration would be low due to the highly charged nature of these particles and any sulfite that did penetrate would be converted to sulfate by the enzyme sulfate oxidase. As used in cosmetics, therefore, these ingredients would not present a genotoxicity risk. The Cosmetic Ingredient Review Expert Panel concluded that Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are safe as used in cosmetic formulations.

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.

Food allergy: a practice parameter update-2014

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology (JCAAI). The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Food Allergy: A practice parameter update-2014." This is a complete and comprehensive document at the current time. The medical environment is a changing one, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, ACAAI, and JCAAI. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Are excipients really inert ingredients? A review of adverse reactions to excipients in oral dermatologic medications in Canada

BACKGROUND

Whereas several literature reviews have discussed the role of excipients in drug-related reactions, no article has focused specifically on those found in oral dermatologic medications.

METHODS

The Compendium of Pharmaceuticals and Specialties (CPS) was used to reference the inert ingredients found in oral dermatologic medications. An extensive literature review was subsequently conducted using PubMed and MEDLINE to document adverse reactions to these excipients.

RESULTS

Sixty-three oral dermatologic medications were reviewed. Lactose was commonly used as a filler. Several medications indicated that they were dye, tartrazine, or gluten free. Three medications were found to contain soybean oil and one was found to contain peanut oil.

CONCLUSIONS

Although there are documented reactions to excipients in other products in the literature, few reports outline reactions to excipients in oral dermatologic medications. Whether this low frequency is accurate or whether it is due to a lack of reporting remains unknown. If the latter reasoning is correct, dermatologists must be more aware of these possible reactions. This article serves as a reference guide for dermatologists to aid in prescribing medications to individuals with known sensitivities and to assist in working up patients with suspected reactions to inert ingredients.

The genotoxic effect of potassium metabisulfite using chromosome aberration, sister chromatid exchange, micronucleus tests in human lymphocytes and chromosome aberration test in bone marrow cells of rats

Potassium metabisulfite (PMB) is used as an antimicrobial substance in many kinds of foods. In the present study, the effects of PMB on chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) formation in human lymphocytes and as well as its effect on CAs in bone marrow cells of rats were investigated. The human lymphocytes were treated with 25, 50, 100, and 200 microg/ml of PMB for 24 and 48 hr. PMB was also intraperitoneally (ip) injected to the rats as a single dose of 150, 300, and 600 mg/kg body weight (b.w.) for 12 and 24 hr before sacrifice. PMB induced abnormalities such as structural and numerical (total) CAs, SCEs, and MN formations in a dose dependent manner in the lymphocytes of the 24- and 48-hr treatment periods. In addition, PMB showed a cytotoxic effect by decreasing the replication index (RI), mitotic index (MI) and nuclear division index (NDI) in a dose dependent manner in human lymphocytes. The compound induced CA as well and decreased the MI in bone marrow cells of rats. It might be concluded that PMB had a high genotoxic and cytotoxic risk.

Pitfalls in drug allergy skin testing: false-positive reactions due to (hidden) additives

Skin testing for drug hypersensitivity is a valuable diagnostic tool and a well established procedure for betalactams and corticosteroids. Although appropriate patch, prick or intracutaneous testing usually permits unequivocal interpretation, the possibility of false-positive reactions must be kept in mind. We report two patients, one with a suspected penicillin allergy and one with a suspected steroid allergy, in whom positive skin tests initially yielded a false diagnosis. In both cases, other findings were inconsistent with the positive skin tests. Therefore, further investigations were performed. After the test preparations had been analysed, the skin test was extended to include the additives, which then yielded the diagnosis of sensitization to the surfactant polysorbate 80 (PS 80, contained in the penicillin test solution) and the emulsion stabilizer carboxymethylcellulose (CMC, contained in the steroid preparation), respectively. It should be noted that positive reactions to test solution additives, as in the first case, may lead to a lifelong false diagnosis of (penicillin) allergy, whereas an undiagnosed allergy to additives in parenteral applications, as in the second case, might prove fatal.

Adverse reactions to food additives

OBJECTIVES

To summarize the literature related to the classification of food additives and their reported adverse reactions and to provide a practical approach for evaluation of patients suspected of having such reactions.

DATA SOURCES

Information was derived from selected reviews and original articles published in peer-reviewed journals and from authoritative textbook chapters, supplemented by the clinical experience of the authors.

STUDY SELECTION

Priority was given to studies that used blinded, placebo-controlled oral challenges to confirm adverse reactions to food additives. In addition, selected, appropriately evaluated case reports are included.

RESULTS

A large number of food additives are widely used in the food industry. Adverse reactions to additives seem to be rare but are likely underdiagnosed in part due to a low index of suspicion. Numerous symptoms have been attributed to food additive exposure, but the cause-and-effect relationship has not been well demonstrated in all.

CONCLUSIONS

Reactions to food additives should be suspected in patients who report symptoms to multiple unrelated foods or to a certain food when commercially prepared but not when homemade and the allergy evaluation rules out a role for food protein. It is also prudent to investigate food additives in patients considered to have idiopathic reactions. There is a minor role for skin testing or in vitro testing. Oral challenge testing with common additives, preferably preceded by a trial of an additive-free diet, is the definitive procedure for detecting the offending agent. Once the specific additive is identified, management is basically avoidance of all its forms.

Adverse reactions to food additives

There are thousands of additives used by the food industry for a variety of purposes in the foods we eat. However, only a small number have been implicated in causing adverse reactions in humans. Although there are reported cases of individuals who have reactions to single additives, most of the medical literature involves patients with asthma or chronic idiopathic urticaria/angioedema whose conditions are exacerbated after ingestion of food additives. Many of these reports are characterized by poorly controlled challenge procedures. Recent studies performed under properly controlled conditions imply that sensitivity to food additives in patients with chronic urticaria/angioedema is very uncommon.

Pickled onion-induced asthma: a model of sulfite-sensitive asthma?

BACKGROUND

Asthma elicited by sulfite ingestion has been mainly described in steroid-dependent and in non-atopic asthmatics. We have studied a group of 18 young extrinsic asthmatics who presented with asthma attacks immediately after eating pickled onions.

OBJECTIVE

The aim of this study is to ascertain if these asthma attacks are elicited by sulfites contained in pickled onions and the influence of the dose and pH of onions.

METHODS

The bronchial hyperreactivity of the patients was assessed by a methacholine challenge test. Oral challenge tests were performed with sodium metabisulfite (MSB) diluted in lemon juice at pH 4.2 and at pH 3.3 (only in patients who did not react with pH 4.2). Two types of pickled onions, Spanish and Dutch pickled onions, were used for oral challenge in seven of the patients. The Monier-Williams method was used to measure the SO2 concentration in pickled onions.

RESULTS

The oral provocation test with MBS, pH 4.2, elicited a positive response in six patients (33.3%) and the test at pH 3.3 was positive in three out of 12. No significant difference in PD20 values was found between these groups. Three of the seven patients challenged with Spanish pickled onions had a positive reaction but had no reaction with Dutch pickled onions. The SO2 concentration in Spanish pickled onions varied between 765 and 1182 ppm while in Dutch pickled onions were 200 ppm; this exceeded the permitted level (100 ppm). SO2 release in Spanish pickled onion samples was nearly 2.5 times higher when the pH of the sample decreased from 4.2 to 3.3.

CONCLUSION

High levels of SO2 in Spanish pickled onions, and their low pH (3.3) would be the responsible factors of the asthmatic outbreaks after ingestion of Spanish pickled onions by these patients.

Sulfite contact allergy

In the last 2 years, 2,894 consecutive eczematous patients were patch tested with sodium metabisulfite 1% pet. Positive reactions were elicited in 50 subjects (1.7%). All 50 patients were also positive to potassium metabisulfite 1% pet. and sodium bisulfite 1% and 5% pet., while only 2 of them were positive to sodium sulfite 1% pet. Prick tests and intradermal tests with a sodium metabisulfite solution (10 mg/ml) were negative. No flare-ups of dermatitis or patch test were provoked by oral challenge with 30 mg and 50 mg of sodium metabisulfite. The dermatitis was taken to be occupational in 7 cases. In only 5 out of 43 non-occupational cases was the positive reaction considered relevant.

Increased electrophoretic mobility of sodium sulfite-treated jack bean urease

Sodium sulfite is a widely used activity-protective agent for the storage of urease. However, this reagent produces a 10% increase in the anodic electrophoretic mobility of native urease. Changes in the hydrodynamic properties of the enzyme are not involved in that modification. The observed change is related to an increased negative charge of the protein molecule in the presence of sodium sulfite. The results are discussed in terms of sulfitolysis of the single disulfide bond in the urease monomer. It is remarkable that the modification occurs at neutral pH. Our results show that removing sodium sulfite and reversing its effect by treatment with 2-mercaptoethanol are required prior to any study involving native urease.

Review of parenteral sulfite reactions

Sulfiting agents are commonly used in parenteral emergency drugs, including epinephrine, dexamethasone, dobutamine, dopamine, norepinephrine, phenylephrine, procainamide, and physostigmine. Published anaphylactic or asthmatic reactions have been associated with sulfited local anesthetics, gentamicin, metoclopramide, doxycycline, and vitamin B complex. The reactions differ from those caused by foods, in that they have a rapid onset, have no predilection for steroid-dependent asthmatics, and do not always coincide with a positive oral challenge. The mechanism is unknown, but may involve a dose-related reaction with disulfide bonds on sympathetic and parasympathetic receptor membranes. Patients with a history of positive oral challenge to 5-10 mg of sulfite may be at increased risk of developing a reaction to parenteral sulfites. Despite documentation of sensitivity, sulfites should not be withheld from patients experiencing a life-threatening emergency. Non-sulfited alternatives are often available, and should be used preferentially.

Site-specific fragmentation and modification of albumin by sulfite in the presence of metal ions or peroxidase/H2O2: role of sulfate radical

Exposure of albumin to sulfite in the presence of Co(II) or peroxidase/H2O2 caused site-specific fragmentation, which was not due to cleavage of methionyl nor tryptophanyl peptide bonds. The reaction of GlyPro with sulfite in the presence of Co(II) or peroxidase/H2O2 led to Gly liberation, suggesting the oxidative cleavage of protein at Pro residues. Sulfite plus Co(II) induced bityrosine production, Trp loss and a new Trp-derived fluorescence. ESR-spin trapping method provided evidence for the formation of sulfate radical (SO4.-) during Co(II)-catalyzed autoxidation of sulfite. The order of reactivity with SO4.- seemed to be Trp greater than GlyPro greater than GlyGly approximately Gly approximately Pro. The results suggest that SO4.- plays an important role in fragmentation and modification of albumin.

Diagnosis of sulfite and aspirin sensitivity

In addition to the well-recognized allergic responses of individuals to high mol wt substances, such as pollens, molds, and animal dander, susceptible asthmatics may also experience adverse reactions to low mol wt substances such as sulfites, ASA, and NSAIDs. The diagnosis of sulfite and aspirin sensitivity can only be made by appropriately conducted provocative challenge. Every precaution should be taken to assure the safety of the patients, since life-threatening reactions can occur. A better understanding of the mechanism or mechanisms involved in the adverse reactions to these substances will not only provide information to better diagnose the reaction, but also improve our understanding of the treatment of asthma.

The results of skin testing with food additives and the effect of an elimination diet in chronic and recurrent urticaria and recurrent angioedema

Ninety-one subjects suffering from chronic or recurrent urticaria or recurrent angioedema of 2 months to 17 yr duration were skin-prick and scratch tested with 18 various food additives. Twenty-four of the subjects (26%) had at least one histamine equivalent skin test (ST) reaction. In contrast, only 24 (10%) of 247 non-urticaria control subjects showed comparable results. An oral provocation test with food additives was carried out on 10 of the 24 ST-positive subjects with urticaria or angioedema, but only one positive reaction, caused by benzoic acid, was recorded. All 91 subjects were advised to follow an additive-free diet. The effect of the diet was investigated with a retrospective postal survey. Twenty-three ST-positive subjects returned the questionnaire, 18 had followed the diet, and 16 (89%) of these 18 had experienced marked relief of their symptoms. Correspondingly, 42 of the 47 ST-negative subjects had followed the diet, and 17 (40%) had improved. The difference was significant (P less than 0.05). Our results suggest that skin tests with food additives can be used to measure skin hyperreactivity and that they may have a predictive value in identifying patients who will respond to an additive-free diet.

[Severe complications related to metabisulfites]

Metabisulfite intolerance is encountered in 8 p. 100 of cases of extrinsic asthma and in 20 p. 100 of cases of the "aspirin triad" with nasosinusal polyposis, asthma and aspirin sensitivity. The possibility that anaphylactoid shock or acute severe asthma leading to status asthmaticus, might be related to sulfite sensitivity must be well known. Two case reports are set out. The first observation is that of a 35-year-old woman suffering from intrinsic asthma with alcohol intolerance, who developed status asthmaticus a few minutes after intravenous administration of Doxycycline associated with a metabisulfite preservative. The other 33-year-old patient presented with an acute bronchospasm in the course of a fiberoscopy using Lidocaine associated by mishap with epinephrine, as local anesthetic. The authors point to the miscellaneous drugs containing sulfites, that are employed in asthmatics by different routes, i.e. parenteral, oral, inhalational and other local treatments. Heavy metabisulfite intake may also arise from daily alcohol consumption. Sulfite intolerance could contribute to the persistence of chronic inflammatory processes in bronchial asthma and therefore should be systematically investigated.

The laboratory evaluation of IgE antibody to metabisulfites in patients skin test positive to metabisulfites

An immediate-type hypersensitivity reaction has been proposed as one possible mechanism in which metabisulfites (MBSs) cause reactions. As demonstrated with certain occupational chemicals, we proposed that MBS might conjugate with human proteins, such as human serum albumin, and then cause an immunologic response. Because we had identified no reactions to MBS at the Northwestern Allergy Service, we used sera from four patients reported elsewhere as having positive skin tests and positive oral challenges to sulfites. We attempted to demonstrate, both in vitro by ELISA and in vivo by passive cutaneous transfer to monkey, evidence for IgE-mediated hypersensitivity to MBSs. Our results demonstrated that there is evidence of IgE antibody by passive transfer for one patient studied, but no evidence of IgE antibody by ELISA to an MBS-albumin conjugate in any of the four patients. This study illustrates the complexities involved in the evaluation and mechanism of MBS-induced disease and the caution with which results must be interpreted.

Hypersensitivity reactions to food additives

Only seldom have food additives been shown to cause true allergic (immunological) reactions. Adverse effects due to various pharmacological or other mechanisms are much more common. The individual tolerance may be decreased for one reason or another, and may fluctuate from time to time. Many patients suffering from food additive reactions have atopic constitutions and such clinical symptoms as flexural dermatitis, rhinitis and asthma. The most important skin symptoms caused by food additives are urticaria, angioneurotic edema, and contact urticaria. Azo dyes, benzoic acid and several other common food additives may aggravate or, more rarely, even cause urticaria. Spices are one of the most common causes of immunological contact urticaria. Non-immunological contact urticaria is produced by numerous spices, benzoic acid, sorbic acid, cinnamic acid, and many essential oils. Asthma and rhinitis are the main hypersensitivity symptoms in the respiratory tract, and azo dyes, benzoic acid, and sulfitic food additives are the most common causative agents. Systemic and respiratory reactions to food colorants and benzoates have been claimed to occur more frequently in acetylsalicylic acid- (ASA-)sensitive patients than in non-reactors. Hypersensitivity reactions in organs other than the skin and respiratory tract are rare or poorly documented. Psychological factors play an essential role in both food and food additive reactions.