[Severe anaphylactic shock with heart arrest caused by coffee and gum arabic, potentiated by beta-blocking eyedrops]

Additives and preservatives: Role in food allergy

Food additives are natural or synthetic substances added to foods at any stage of production to enhance flavor, texture, appearance, preservation, safety, or other qualities. Common categories include preservatives and antimicrobials, colorings and dyes, flavorings, antioxidants, stabilizers, and emulsifiers. Natural substances rather than synthetics are more likely to cause hypersensitivity. Although rare, food additive hypersensitivity should be suspected in patients with immunoglobulin E (IgE)-mediated reactions to multiple, unrelated foods, especially if the foods are prepared outside of the home or when using commercial products. A complete and thorough history is vital. Skin prick testing and/or specific IgE blood testing to food additives, if available, additive avoidance diets, and blind oral challenges can help establish the diagnosis. Once an allergy to a food additive is confirmed, management involves avoidance and, if necessary, carrying self-injectable epinephrine.

[Drugs as risk factors of food anaphylaxis in adults]

Anaphylaxis is the most severe type of food allergy. Factors of risk are advanced age, cardiopathy, asthma, mastocytosis. Age may be linked to an increased consumption of drugs: aspirin, nonsteroidal anti-inflammatory drugs, beta-blockers, inhibitors of angiotensin converting enzyme (ACE). A case-control study comparing anaphylaxis and mild food allergies has shown a sharp increase of consumption of these drugs in patients with anaphylaxis, with odds ratio respectively of 10.8 [CI 95%: 3.10-41.3], 8.2 [CI 95%: 1.37-62.51], 6.8 [CI 95%: 1.78-27.78] and 13 [CI 95%: 1.34-310.38]. Besides, exercise potentiates the relative risk of drug consumption. Predominant mechanisms could be an increase of gut permeability enhancing the passage of food allergens in the mucosa and in blood, and the inhibition of ACE, so that the angiotensin homeostatic mechanism deteriorates. Main sites of interference may be endothelium and gut epithelium. Preventive measures excluding the intake of aspirin and nonsteroidal anti-inflammatory drugs before the meals can be recommended for food allergic and food sensitized adults. Treatment of hypertension can address to other families of drugs than ACE inhibitors (ACEI) and beta blockers. The benefit-risk ratio of beta blockers and ACEI has to be carefully considered in the case of cardiopathy. double dagger.

Prise en charge d'une réaction anaphylactique en extrahospitalier et aux urgences: revue de la littérature

Care and therapy of patients experiencing an anaphylactic reaction should be known by the physicians working in the emergency medical unit or in pre-hospital care. The epidemiology of these reactions varies according to the countries. The main aetiologies are due to food, hymenoptera or drugs. The clinical scale proposed by Ring and Messmer aims to classify the reactions in 4 grades according to their severity and is useful to stratify therapy. According to the grade of the reaction, the drug of choice for the treatment of anaphylaxis is epinephrine associated to vascular expansion. Anaphylaxis during pregnancy is described. Patients who experienced an immediate hypersensitivity reaction should undergo an allergological investigation to prove the immune mechanism and to identify the culprit allergen. Reporting to the Drug Safety Monitoring Authorities when a drug is implicated should not be forgotten.

Paradoxical reaction to epinephrine induced by beta-blockers in an anaphylactic shock induced by penicillin

Increased risk of severe and resistant anaphylactic shock is a rare and not widely known adverse effect of beta-blocker treatment. It is illustrated in a case of refractory anaphylactic shock occurring in a 47-year-old woman who received beta-blockers. Actually, beta-blockers increase the release of anaphylactic mediators, decrease the cardiovascular compensatory changes to the anaphylactic shock and promote paradoxical reflex vagotonic effects when using epinephrine.

Final report of the safety assessment of Acacia catechu gum, Acacia concinna fruit extract, Acacia dealbata leaf extract, Acacia dealbata leaf wax, Acacia decurrens extract, Acacia farnesiana extract, Acacia farnesiana flower wax, Acacia farnesiana gum, Acacia senegal extract, Acacia senegal gum, and Acacia senegal gum extract

These ingredients are derived from various species of the acacia plant. Only material derived from Acacia senegal are in current use according to industry data. The concentration at which these ingredients are reported to be used ranges from 9% in mascara to 0.0001% in tonics, dressings, and other hair-grooming aids. Gum arabic is a technical name for Acacia Senegal Gum. Gum arabic is comprised of various sugars and glucuronic acid residues in a long chain of galactosyl units with branched oligosaccharides. Gum arabic is generally recognized as safe as a direct food additive. Little information is available to characterize the extracts of other Acacia plant parts or material from other species. Acacia Concinna Fruit Extract was generally described as containing saponins, alkaloids, and malic acid with parabens and potassium sorbate added as preservatives. Cosmetic ingredient functions have been reported for Acacia Decurrens Extract (astringent; skin-conditioning agent--occlusive) and Acacia Farnesiana Extract (astringent), but not for the other Acacias included in this review. Toxicity data on gum arabic indicates little or no acute, short-term, or subchronic toxicity. Gum arabic is negative in several genotoxicity assays, is not a reproductive or developmental toxin, and is not carcinogenic when given intraperitoneally or orally. Clinical testing indicated some evidence of skin sensitization with gum arabic. The extensive safety test data on gum arabic supports the safety of Acacia Senegal Gum and Acacia Senegal Gum Extract, and it was concluded that these two ingredients are safe as used in cosmetic formulations. It was not possible, however, to relate the data on gum arabic to the crude Acacias and their extracts from species other than Acacia senegal. Therefore, the available data were considered insufficient to support the safety of Acacia Catechu Gum, Acacia Concinna Fruit Extract, Acacia Dealbata Leaf Extract, Acacia Dealbata Leaf Wax, Acacia Decurrens Extract, Acacia Farnesiana Extract, Acacia Farnesiana Flower Wax, Acacia Farnesiana Gum, and Acacia Senegal Extract in cosmetic products. The additional data needed to complete the safety assessment for these ingredients include (1) concentration of use; (2) identify the specific chemical constituents, and clarify the relationship between crude Acacias and their extracts and the Acacias and their extracts that are used as cosmetic ingredients; (3) data on contaminants, particularly relating to the presence of pesticide residues, and a determination of whether Acacia melanoxylon is used in cosmetics and whether acamelin (a quinone) and melacacidin (a flavin) are present in the Acacias that are being used; (4) skin sensitization study (i.e., dose response to be determined); (5) contact urticaria study at use concentration; and (6) ultraviolet (UV) absorption spectrum; if there is significant absorbance in the UVA or UVB range, then a photosensitization study may be needed. It was also noted that other data may be needed after clarification of the chemical constituents of the Acacia-derived ingredients.

Adult food allergy

Adult food allergy is estimated at approximately 3.2% worldwide. The persistence of childhood food allergy is unusual, peanut allergies excepted. Once established in adults, food allergy is rarely cured. Factors favoring the acquisition of allergy could be sensitization to pollens, occupational sensitization by inhalation, drugs (such as tacrolimus), and sudden dietary changes. Severe anaphylaxis and oral allergy syndrome are frequent. The fatality risk is estimated at 1% in severe anaphylaxis. Risk factors for severe anaphylaxis are agents causing increased intestinal permeability, such as alcohol and aspirin. b-blockers, angiotensin-converting enzyme (ACE) inhibitors, and exercise are other factors. Gastrointestinal food allergy remains, to a large extent, undiagnosed in adults. Food allergens are mainly fruit and vegetable, related to pollen sensitizations, or to latex allergy. Wheat flour allergy is increasing. The diagnosis relies on prick skin tests, detection of specific IgEs, and standardized oral challenges. Strict avoidance diets are necessary. Specific immunotherapy to pollens may be efficient for cross-reactive food allergies.

Epidemiology of life-threatening and lethal anaphylaxis: a review

Severe anaphylaxis is a systemic reaction affecting two or more organs or systems and is due to the release of active mediators from mast cells and basophils. A four-grade classification routinely places 'severe' anaphylaxis in grades 3 and 4 (death could be graded as grade 5). Studies are underway to determine the prevalence of severe and lethal anaphylaxis in different populations and the relative frequencies of food, drug, latex and Hymenoptera anaphylaxis. These studies will also analyse the risk arising from the lack of preventive measures applied in schools (personalized management protocols) and from the insufficient use of self-injected adrenalin. Allergy-related conditions may account for 0.2-1% of emergency consultations. Severe anaphylaxis affects 1-3 per 10 000 people, but for the United States and Australia figures are even higher. It is estimated to cause death in 0.65-2% of patients, i.e. 1-3 per million people. An increased prevalence has been revealed by monitoring hospitalized populations by reference to the international classification of disease (ICD) codes. The relative frequency of aetiological factors of allergy (food, drugs, insects and latex) varies in different studies. Food, drug and Hymenoptera allergies are potentially lethal. The risk of food-mediated anaphylaxis can be assessed from the number of personalized management protocols in French schools: 0.065%. Another means of assessment may be the rate of adrenalin prescriptions. However, an overestimation of the anaphylaxis risk may result from this method (0.95% of Canadian children). Data from the literature leads to several possibilities. First, a definition of severe anaphylaxis should be agreed. Secondly, prospective, multicentre enquiries, using ICD codes, should be implemented. Moreover, the high number of anaphylaxis cases for which the aetiology is not identified, and the variation in aetiology in the published series, indicate that a closer cooperation between emergency specialists and allergists is essential.

Adrenaline in the treatment of anaphylaxis: what is the evidence?

Adrenaline (epinephrine) is the recommended first line treatment for patients with anaphylaxis. This review discusses the safety and efficacy of adrenaline in the treatment of anaphylaxis in the light of currently available evidence. A pragmatic approach to use of adrenaline auto-injectors is suggested.

Allergy to date fruits: characterization of antigens and allergens of fruits of the date palm (Phoenix dactylifera L.)

BACKGROUND

Date-palm (Phoenix dactylifera L.) fruits are eaten daily by most inhabitants of the Middle East and the neighboring countries. Recent reports have indicated that dates are allergenic. This study aimed to investigate the antigenic and allergenic potential of date fruits.

METHODS

Date-fruit extracts from eight cultivars were evaluated in skin prick tests (SPT) in an atopic population, used to produce antisera, analyzed by SDS-PAGE, and fractionated by gel-filtration chromatography. Sera from SPT-positive individuals were evaluated by ELISA and RAST, and in anti-igE immunoblot experiments.

RESULTS

About 13% of patients were SPT-positive for at least two extracts. SDS-PAGE of whole extracts revealed 15-18 protein bands of 6.5->100 kDa, and Sephacryl S-200 fractions gave distinct peptide bands. RAST and anti-IgE ELISA gave a range of positive results, which could be abrogated when sera were preabsorbed with fruit extracts. IgE immunoblots of different extracts with pooled positive sera revealed different anti-IgE-binding immunoprints. All the positive sera from fruit-allergic and pollen-allergic individuals bound strongly to two anti-IgE reactive bands of 6.5 to 12-14 kDa and 28-33 kDa, respectively, and about 50% of sera bound to a 54-58-kDa band.

CONCLUSIONS

These results strongly indicate that 1) date-palm fruit is a potent allergen 2) sera from fruit-allergic as well as pollen-allergic patients recognize common fruit-specific epitopes 3) there is heterogeneity in patient responses to the different extracts.