Immunothérapie et allergie alimentaire

Immunotherapy trials on food allergy were published some years ago and few of them were randomized. The protocols used varied and IgE-mediated food allergies were the first studied. Immunotherapy is mainly indicated for persistent food allergy after the usual age of recovery. Other factors, such as the dose of the allergen and the nature of the symptoms due to food allergy, are less well-defined with regard to indications for immunotherapy. Different techniques are available: the subcutaneous route, with well-known adverse effects when currently available extracts are used; the oral route, with efficacy in a third of the cases and the sublingual route, which seems to be promising. The real effect of immunotherapy, whether persistent, transitory or merely an increase in the amount of food tolerated, remains to be defined.     

Nouveautés en pneumologie et en allergologie pédiatriques

Asthma and other allergic conditions are priority research subjects because they are major public health problems world-wide. The management of severe allergic asthma has benefited from the development of a new class of drugs, anti-IgE antibodies (omalizumab). Other molecules being studied in adult asthmatics include monoclonal antibodies and fusion proteins whose action is to block bronchial inflammation at different levels. Considerable progress has been made in the understanding of the genesis of asthma and allergy. It appears that the early years of life have a fundamental importance in the natural history of allergic diseases and, in particular, of asthma; this makes it important to act early on the process, that is, from the earliest age possible. Specific immunotherapy, by injection or sublingually, may have a positive effect on the natural history of allergy, making it possible to predict the development of new sensitivities and reduce the risk of developing asthma. The coming years will probably reveal which therapeutic measures will be effective in preserving the respiratory capital of the asthmatic infant.     

Quoi de neuf en allergologie pédiatrique en 2006-2007 ? Partie 3: Allergie cutanée, alimentaire, médicamenteuse et aux insectes (une revue de la littérature internationale d’octobre 2005 à septembre 2007)

Most sensitizations in children with atopic dermatitis are non pathogenic. Thus, responses in prick-tests, specific IgE determinations and patch-tests should be carefully evaluated based on the clinical history of the children or responses in challenge tests. Moreover, although atopy patch-tests are highly specific, they have a low sensitivity. Food eviction is indicated in a few children only, since they may be responsible for anaphylactic reactions induced by accidental ingestion of the food or oral challenge tests. The predictive value of serum specific IgE to foods depends on the food investigated, the age of the children, their allergic disease (atopic dermatitis, urticaria/angioedema, anaphylaxis) and, may be, on their ethnical origin. The prevention of food-induced severe reactions is based on eviction. However, several studies suggest that oral desensitization to foods may be efficient. Most frequent reactions in children hypersensitive to antalgics, antipyretics and nonsteroidal antiinflammatory drugs are oedema (facial oedema especially) and urticaria. Usually, the severity of the reactions increases from one treatment to another one and with the dose of drug administered to the children. Diagnosis is based on a convincing clinical history or on challenge tests. Skin tests with vaccines should be performed according to a standardized procedure because they may give false positive responses. Most latex sensitizations detected by skin prick-tests and, especially, specific IgE determinations are non pathogenic. The prevention of reactions to latex is based on eviction. However, preliminary results suggest that sublingual desensitization with a latex extract is efficient and well-tolerated.     

Définitions des termes utilisés en allergologie alimentaire chez l’enfant

In so far as there are no recent medical references that specify terms used in allergy, and particularly terms dealing with food allergy, it seemed to us that it would be of use to compile a glossary that would be helpful in daily practice. The defined terms (plus comments) have been retained according to sequences that correspond to steps in a food allergy work-up. The following terms are entered successively in this review: atopic dermatitis; SCORAD; asthma; pulmonary function tests; medications for children; symptoms and severity of food allergies; immediate skin tests; intradermal tests or “atopy patch-tests”; allergen-specific and total serum IgE levels; oral provocation test; labial provocation test; other tests used in allergy work-ups; allergy, hypersensitivity, atopy; allergens, allergies, sensitizations, allergic cross-reactions; treatment of an allergic reaction.     

Détermination des seuils de réactivité au cours des allergies alimentaires

It is important for an individual allergic to food to be aware of the threshold (the minimal amount) of the allergenic food that can trigger a reaction. This information is equally essential to the food-processing industry for labeling of pre-packaged foodstuffs. Three methods are available to determine the threshold: case reports, statistical methods and oral provocation tests. Published data available at present allow only limited analysis for three foods (cow milk, chicken egg and peanut). In addition, the absence of standardized oral provocation tests limits determination of thresholds.     

Otite séreuse et allergie

Respiratory and/or food allergy is common in children. Serous otitis media is also very frequent in children, especially those between three and six years of age. On the other hand, in spite of promising animal studies, a cause-and-effect relation between these two conditions in man has not been established. Concerning the treatment, avoidance of food allergens may be as efficacious for an active serous otitis media as for avoidance of a new episode. Conversely, antihistamines do not appear to be efficacious, at least with respect to being curative.     

Allergie à la farine de blé chez l’adulte

The clinical manifestations of allergy to wheat flour are similar to those of allergies to other foods. In adults, food-dependent exercise-induced anaphylaxis, chronic urticaria, and gastrointestinal food allergies (that is, irritable bowel syndrome, eosinophilic colitis, ulcerative colitis) are the most frequently described clinical manifestations of allergy to wheat. Wheat isolates, used as binders and emulsifiers in the food industry, are neo-allergens resulting from chemically induced desamidation of wheat gluten (heating at high temperature in an acidic medium). Wheat isolate allergens can induce severe systemic reactions (e.g., urticaria) and anaphylactic shock. Diagnosis consists of three steps: a suspicion based on the patient's history, identification of the allergen by skin testing and by laboratory tests, and confirmation by oral challenge or by an avoidance regime.     

Induction de tolérance orale aux aliments chez l’enfant : aspects pratiques

Specific oral tolerance induction (SOTI) to food is a new topical-therapeutic approach of food allergy. When successful, it improves significantly the patients’ quality of life. SOTI’s practical aspects for child are discussed from our recent experience concerning cow milk, hen’s egg and wheat. Family’s motivation and education are crucial questions to achieve SOTI correctly. A detailed information of possible side effects is essential.     

Histoire de l'allergie alimentaire : des précurseurs à l'histoire contemporaine

Food allergies are an important public health problem. Relatively unheard of during the 1970–1980 s, they had almost always been associated with the same allergens (cow milk, chicken eggs, and fish). Since then, they have become more frequent and more varied, involving about 4% of the general population of all ages; the prevalence may even be 5–6% or more among children. They are also becoming more and more severe, and interfering more in daily living. Beginning in the 1980 s, the story of food allergy has been marked by the explosion of the occurrence of peanut allergy, the prevalence of which has at least doubled over the past five years. Another important tendency has been an increase in the frequency of allergy to shelled fruits (e.g. exotic nuts) and to certain plant allergens (e.g. sesame, buckwheat and wheat). There has also been an increase in the number of near-fatal and fatal cases of food-related anaphylaxis, justifying the establishment of a monitoring network. The workup of food allergies has become more standardized, allowing a definitive diagnosis to be more easily established, thus justifying avoidance of the responsible substance. Indeed, until recently, in the absence of effective preventive measures and a good risk-benefit ratio, the prevention of food allergies depended on avoidance of the responsible food(s), which recommendation is nevertheless often not followed as prescribed. Other preventive measures (antihistamines, corticosteroids, adrenalin auto-injectors) are then adopted to avoid recurrences, which can be considered as evidence of treatment failure. Recent years have been marked by standardization of preventive measures based on the Project of Individual Care and by the establishment of educational protocols. The future may see the development of specific immunotherapy (until now, difficult and dangerous), modification of food allergens, and treatments that block IgE-dependant allergic reactions. For example, the preliminary results of a clinical trial of sublingual immunotherapy with hazelnut appear to be promising. Considering the difficulty of diagnosis and prevention, the social and psychological repercussions of food allergies are considerable for both children and their families.     

Test de provocation par voie orale aux aliments chez l'enfant. Quand,pour qui et comment ? Conséquences

Whatever results are, oral food challenges (OFC) will have consequences, particularly on diet and emergency kit. Positive OFC, negative OFC and food specificities are discussed, according to the literature review. In case of positive OFC, the management and monitoring of persistent food allergy is specified. Practical recommendations are suggested.     

Test de provocation par voie orale aux aliments chez l'enfant. Quand,pour qui et comment ? Interprétation

Oral food challenges (OFC) have to be carefully interpreted. OFC prove the food allergy or persistent food allergy. OFC prove also the absence or the cure of food allergy. Objective and subjective signs are distinguished. Cutaneous and gastrointestinal symptoms are more frequent than respiratory or systemic symptoms. Delayed reactions, isolated or associated, have to be taken into account. In some cases, the OFC cannot be interpreted. Negative double-blind placebo-controlled food challenge must be confirmed by an open manner.     

Quoi de neuf en allergologie pédiatrique en 2005 ? Partie 4. Allergie cutanée,alimentaire, médicamenteuse et aux insectes (Une revue de la littérature internationale d'octobre 2004 à octobre 2005)

Allergological work-up and treatment of french children with atopic dermatitis have been the subject of a recent consensus. Food avoidance is useless for prevention of atopic dermatitis, and should be indicated in children with severe atopic dermatitis associated with food allergy only. Exposure, sensitization and allergy rates to nuts increase with age, and avoidance of nuts (even tolerated) is recommended in young children allergic to one or several nuts to prevent the risk of sensitization and allergy to an increasing number of nuts. Threshold values of skin prick-tests and specific IgE determinations with a 90-100% predictive value for food allergy are highly variable from one study to another one, and depend on numerous factors such as age of the children, the allergens used, etc. The diagnostic value of patch-tests and skin application food tests remains controversial. Treatment of food allergy is based on the eviction of the allergenic foods. However, probiotics and « desensitization » to foods may be efficacious in some patients. In children that have outgrown their food allergy, tolerance should be maintened by regular consumption of the foods. However, the parents should be informed that relapses requiring an emergency treatment may occur. Finallly, in children as in adults, repeated mosquito bites induce a desensitization, and most children outgrow their allergy between five to fourteen years.     

Les allergènes de l’arachide et des fruits à coque

The foods contain several hundreds of proteins for which only a small number, called allergens, is responsible for allergic reactions. The edible tree nuts (almond, walnut, cashew, Brazil nut, macadamia nut, pecan, Nangai nut, pistachio, pine nut, chestnut and coconut) consist of approximately, 15% of proteins. The objective of this review is to present, from a biochemical point of view, the allergens of these nuts known at the present time and to discuss what this type of information can bring in the comprehension of the mechanisms of cross reaction.     

Réactions allergiques et pseudoallergiques aux médicaments et substances biologiques chez l’enfant

Five to 20% of subjects of all ages report suspected allergic reactions to drugs and biological substances. Children may be less affected than adults, but this difference is disputed and probably results from differences in drug exposure. Most frequently suspected drugs are antibiotics, betalactams especially, antipyretics, analgesics and nonsteroidal anti-inflammatory drugs. Most frequent reactions are morbilliform/maculopapular rashs, urticaria and angioedema. Other cutaneous and respiratory reactions, and severe anaphylactic and anaphylactoid reactions, are rare. The results of allergological studies suggest that, except for a few types of reactions (anaphylactic and immediate reactions, potentially harmful toxidermias) and for very specific drugs (i.e. latex and myorelaxants), most reactions to commonly used drugs and biological substances in children do not result from drug hypersensitivity, but are rather a consequence of the infectious and/or inflammatory diseases for which the drugs have been prescribed. The reactions may also result from complex interactions between drugs, immune system and “danger” signals provided or induced by infectious and/or inflammatory diseases. Diagnosis is based above all on a detailed analysis of clinical history, skin tests (if validated) and challenge tests (if indicated). In children with drug allergy or intolerance, prevention of relapse is based on a rigourous avoidance of the responsible drug and cross-reacting drugs.     

Spécialisation en allergologie et immunologie clinique en Suisse

The incidence of allergic and immunological diseases has been increasing for several years and affects a significant portion of the population. The treatment of these diseases requires appropriate training in allergology and clinical immunology, which justifies the creation of allergy as a specialty. In Switzerland, this training program lasts six years: three years of basic training (internal medicine or paediatrics and dermatology) and three years of specialized training (clinical immunology and allergology). During this period, the physician acquires skills in various fields of this broad discipline, in particular epidemiology, pathophysiology, diagnosis, treatment and prevention. The trainee is sanctioned by a final exam which includes both a written and an oral exam. The goal is to get in line progressively with the European level. Finally, it would be desirable to develop a European specialist title that would lead to standardized training programs in the different countries.     

Un cas de syndrome de Hoigné lors d’une injection intraveineuse de ceftriaxone

Introduction

Hoigne's syndrome is characterized by the development of acute clinical manifestations which are mainly psycho-sensorial. Classically, these features immediately follow the injection of procaine penicillin G.

Case report

We report a 59-year-old man who presented with psycho-organic manifestations that occurred just after the intravenous injection of ceftriaxone; to our knowledge, this is the first case of Hoigne's syndrome reported after an injection of this antibiotic.

Conclusion

The pathophysiologic basis of this syndrome is still unknown. It is important to keep in mind its clinical characteristics, which may mimic immuno-allergic symptoms. It should be differentiated from anaphylactic manifestations because Hoigne's syndrome allows the continuation of the treatment.