Oral desensitization in children with milk and egg allergies obtains recovery in a significant proportion of cases. A randomized study in 60 children with cow's milk allergy and 90 children with egg allergy

BACKGROUND

Food allergy is treated by avoidance diets in order to prevent anaphylactic reactions and to cure chronic associated symptoms. However, the natural history is left unchanged.

OBJECTIVE

To search for a beneficial effect of an oral desensitization protocol to allergenic foods in IgE-dependent milk or egg allergies in children.

METHODS

60 children with documented cow's milk allergy (13 months-6.5 years), and 90 children with egg allergy (12 months-8 years), were consecutively included after 6-12 months of avoidance diet, if a SBPCFC to 60 ml milk (60 ml) or to 965 mg of raw egg white was negative. They were randomized for uninterrupted avoidance or oral desensitization (group A or OD). Six months later, a new SBPCFC was performed with, up to 200 ml of milk or 7g of raw egg white. Prick tests and specific IgE levels were carried out simultaneously.

RESULTS

Data were obtained for 57 children with CMA (30 A and 27 OD), and 84 children with EA (35 A and 49 OD). The two groups (AD or OD group) were similar with regard to means of ages, the size of PT wheals and the level of IgEs at baseline. MILK ALLERGY: A SBPCFC to milk was positive in 11.1% of those following OD vs. 40% after A (p < .025). The size of PT decreased after OD and increased after A (-3.4 mm vs. +0.84 mm; p < .002). EGG ALLERGY: The SBPCFC to egg was positive in 30.6% after OD vs. 48.6% after A (p < .1). After 6 months, in the OD group, the mean size of the PT and the level of specific IgE were significantly reduced compared to the A group. In the A group, the threshold of reactivity was often lower, or more serious symptoms were observed.

CONCLUSION

Oral desensitization helps the egg and milk allergic children to overcome their allergies. Since the avoidance of these foods is likely to increase sensitization as well as to lower the threshold of reactivity, an active treatment is required. Further attempts to standardize the procedures of oral desensitization are expected.

Food-dependent exercise-induced anaphylaxis--update and current data

Exercise-induced anaphylaxis (EIA) is defined as the onset of allergic symptoms during, or immediately after, exercise, the clinical signs being various degrees of urticaria, angioedema, respiratory and gastrointestinal signs and even anaphylactic shock. Food-dependent exercise-induced anaphylaxis (FDEIA) introduces food in the syndrome and is revealed by a chronological sequence in which food intake, followed by exercise, induces symptoms after a varying period. When the food intake and the exercise are independent of each other, there are no symptoms. FDEIA is not very frequent. Identifying the culprit food allergen depends on the patient's eating habits. Crustaceans and wheat flour are the two commonest but others foods can be implicated. The patho-physiology of FDEIA has not been clearly established but it appears to result from degranulation of mast cells. As with food allergy, FDEIA diagnosis is based on interview, skin and biological tests and challenge. For the clinical signs of allergy, antihistamines, corticosteroids and epinephrine may be administered. Prophylaxis aims to prevent a recurrence; the patient should be given an emergency kit to deal with any recurrent episode. After the food allergen has been identified, it should be avoided for at least 4 to 5 hours before any exercise.

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.

Allergy to nickel in dental alloys

A case of oral allergy to dental alloys is presented, highlighting the interest of dosage of salivary nickel and of flow cytometry showing a selective CD4+ activation. The discrepancy between the rarity of oral allergy to dental alloys and the frequency of nickel sensitization and nickel-induced contact dermatitis leads to discuss the mechanisms of oral tolerance.

Immediate hypersensitivity to chlorhexidine: literature review

Chlorhexidine, an antiseptic belonging to family of biguanides, is used extensively in the medical and surgical environment. Late onset hypersensitivity and eczema occur regularly and are well documented events. Conversely, immediate hypersensitivity, sometimes taking the form of acute urticaria that can result in anaphylactic shock, is rarer. These manifestations can occur during contact of the skin or mucosa with chlorhexidine. Out of the fifty case reports of chlorhexidine-related anaphylaxis published worldwide over the past ten years, fifteen occurred during surgery. Signs generally appear from 15 to 45 minutes after the start of anesthesia. If there is any suspicion of immediate allergy to chlorhexidine, prick-tests or even intradermal reaction (IDR) techniques are highly recommended. In the event of confirmed allergy to chlorhexidine, strict eviction is required, bearing in mind that over a hundred medicinal products currently on the French market contain chlorhexidine.

Severe food anaphylaxis: 107 cases registered in 2002 by the Allergy Vigilance Network

BACKGROUND

The prevalence of food allergies increases, relating to diet modifications. The consumption of new foods--exotic foods or foods originally used for animal feed, new proteins, neo allergens due to the use of new technologies and soon, Genetically Modified Foods--are in the spotlight.

OBJECTIVE

It is essential to develop a system of food allergy vigilance encompassing the full range of foods being consumed. Understanding this imperative leads logically to the suggestion of developing an allergy vigilance network taking advantage of the ongoing experience of allergists "on the ground".

METHODS

The French Allergy Vigilance Network is subscribed to by 302 allergologists (267 of whom are French). The aims of the Network are to record cases of severe anaphylaxis, to establish an epidemiological data bank from prospective multicenter studies, and to monitor the allergic risk from novel foods.

RESULTS

In 2002, 107 cases of severe anaphylaxis were recorded: anaphylactic shock--59.8% (one fatal), systemic reaction--18.7%, laryngeal angio-edema--15.9%, acute severe asthma--5.6% (one fatal). The main allergens identified were peanuts, nuts, shellfish, lupine flour and wheat flour. Action has been taken as a result: information by industry on inadequate labeling, withdrawal of wrongly labeled batches, and university hospital centers have been encouraged to establish the allergenic safety of their catering services.

CONCLUSION

Setting up such a network in other countries would lead to a significant advance in knowledge of the peculiarities of allergies relating to a wide variety of eating habits.

Anaphylactic shock induced by gadoterate meglumine (DOTAREM)

The use of contrast agent for magnetic resonance imaging improves the effectiveness of this diagnostic examination. Complexes of godolinium, which appear to be well tolerated, are used for this purpose. A few cases of anaphylactic shock have been attributed to these agents. We report a case of anaphylactic shock due to gadoterate meglumine (DOTAREM). While undergoing a magnetic resonance imaging examination, a 33-year-old nonatopic female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after she was given injection of epinephrine and her blood volume was restored with intravenous fluids. That DOTAREM had caused this immediate hypersensitivity reaction was proven by the positivity of prick-test and intradermal test at 10-3 (0.37 mg/ml) and in vitro leukocyte histamine release test. The results of these tests indicated that it was the gadoteric acid rather than the meglumine component of DOTAREM that was responsible: positivity of IDR at 10 mg/ml. Skin tests and leukocyte histamine release test to gadopentetate dimeglumine (MAGNEVIST) were negative. In addition of the exceptional character, this observation provides evidence for an immediate hypersensitivity without cross reactivity with gadopentetate dimeglumine.

[Allergies in orthodontics]

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

Thresholds of clinical reactivity to milk, egg, peanut and sesame in immunoglobulin E-dependent allergies: evaluation by double-blind or single-blind placebo-controlled oral challenges

BACKGROUND

The prevalence of food anaphylaxis due to masked allergens has increased within the last 10 years. Contamination of manufactured products by food allergens is a key concern for food industries.

OBJECTIVE

To determine quantities eliciting reactions in patients who have an IgE-dependent food allergy, thanks to standardized oral provocation tests. To evaluate the subsequent levels of sensitivity required for the detection tests of allergens for egg, peanut, milk and sesame.

METHODS

Prick-in-prick tests, Cap system RAST, and single or double-blind placebo-controlled food challenges (SBPCFC or DBPCFC) were performed. The doses of natural food were gradually increased from 5 to 5000 mg for solid food and from 1 to 30 mL for peanut oil, sunflower oil, soy oil and sesame oil.

RESULTS

Data from 125 positive oral challenges to egg, 103 to peanut, 59 to milk and 12 to sesame seeds were analysed. Haemodynamic modifications were observed in 2%, 3%, 1.7%, and 8% of the oral challenges (OCs) to egg, peanut, milk and sesame, respectively. Respiratory symptoms were observed in 12%, 20%, 10% and 42% of egg, peanut milk and sesame allergies, respectively. A cumulative reactive dose inferior or equal to 65 mg of solid food or 0.8 mL of milk characterized 16%, 18%, 5% and 8% of egg, peanut, milk and sesame allergies, respectively. 0.8% of egg allergies, 3.9% of peanut allergies, and 1.7% of milk allergies reacted to 10 mg or less of solid food or to 0.1 mL for milk. The lowest reactive threshold has been observed at less than 2 mg of egg; 5 mg of peanut, 0.1 mL of milk and 30 mg of sesame seed. Ten out of 29 OC with peanut oil, two out of two OC with soy oil and three out of six OC with sunflower oil were positive. Five out six OC with sesame oil were positive: 1 and 5 mL induced an anaphylactic shock.

CONCLUSION

The risk of asthma and anaphylactic shock to sesame and peanut is confirmed. Minimal reactive quantities show that, in order to guarantee a 95% safety for patients who are allergic to egg, peanut and milk, and on the basis of consumption of 100 g of food, the detection tests should ensure a sensitivity of 10 p.p.m. for egg, 24 p.p.m. for peanut and 30 p.p.m. for milk proteins. Oil allergies being considered, the limit of sensitivity should fall to 5 p.p.m.

[The individual reception project (IRP) for anaphylactic emergencies. The situation in France and French overseas territories in 2002]

INTRODUCTION

The management in schools of children with life-threatening or chronic diseases has led to the development of Individual Reception Projects (IRP) since 1993, notified in the state education ministry's circular letter. The aim of this study was to assess the status of such IRPs in France and the French Overseas Territories in the management of food allergy risks.

METHOD

The regional departments of educational promotion were contacted and the survey was run between May and June, 2002. The items of the questionnaire were: the number of IRPs for anaphylactic emergencies, details on the allergies themselves, an overview of the eventual existence of dialogue structures among school physicians, heads of schools, allergists, treatment prescribers and emergency protocols.

RESULTS

The total survey revealed 7482 IRP for anaphylactic reactions to food (14% of the total IRPs). The frequency of IRPs varied greatly depending on the regions. The Paris area represented 36.3% of the total. The Lorraine area: 5.6%, the Haute-Garonne: 5%, and the Bouches-du-Rhône: 3.3%. The IRPs represented 0.002 (Ardèche) to 0.33% (Alpes-de-Haute-Provence) of the school attending population. The mean level was of 0.065%; 71.6% of the IRPs concerned the 1st grade (1 IRP for 1091 children). In decreasing frequency, the allergens concerned were: peanuts, eggs, dried nuts, fish, dried peas and milk. Dialogue structures were established in 38 regions.

DISCUSSION

The IRPs have increased 4-fold since the circular letter in 1999. The enhanced prevalence of numerous (new) allergies to dried nuts and leguminous plants has been emphasized, and peanut allergies have been confirmed. The complexity of managing the IRPs and need for information and training of state education and municipal staff requires the further development of dialogue structures, which are still clearly insufficient.