Two important parameters control skin sensitization to a xenobiotic molecule: its sensitizing potential, an intrinsic property of each chemical, and exposure. It is often difficult to quantify a patient's exposure to a given allergen, which makes it difficult to define strong allergens. Indeed, the prevalence of an allergen, as determined by patch testing, reflects not its strength but a combination of sensitizing potential and exposure. The definition of strong sensitizers is therefore mainly derived from animal experiments where it is possible to assess a sensitization threshold or the dose per square centimeter that is able to induce significant sensitization. It has been shown in a limited number of case studies, that there is a good correlation between sensitization thresholds assessed in mice by the Local Lymph Node Assay (LLNA) and those obtained in humans with the Human Repeated Insult Patch Test (HRIPT). Based on this classification, one can recognize that strong sensitizers are quite common and that the general population is exposed regularly to them. Although the strong sensitizers include a broad diversity of chemicals, they have in common the ability to rapidly modify nucleophilic residues of proteins. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
Sublingual immunotherapy (SLIT) is a non-invasive and efficacious treatment for type I respiratory allergies. To identify candidate adjuvants and galenic formulations capable of inducing tolerance by the sublingual route, an initial screening was carried out using in vitro cocultures of human monocyte-derived dendritic cells and naive CD4(+) T cells. Selected molecules were subsequently tested in a murine asthma model of sublingual immunotherapy in BALB/c mice sensitized to ovalbumin. In this model, we evaluated bronchial hyperreactivity (measured by whole-body plethysmography), pulmonary inflammation (evaluated histologically), and type 2 Immoral and cellular immune responses monitored by Elisa and Elispot techniques in mice sensitized with either soluble or with adjuvant-formulated ovalbumin. Four categories of adjuvant known to increase IL-10 +/- IFN7 production by naive CD4(+) T cells (Treg/Th1) were found to enhance SLIT efficacy in vivo in these mice. These adjuvants were: vitamin D3/dexamethasone, Lactobacillus plantarum, the TLR2 agonist Pam3CSK4, and the TLR4 synthetic ligand OM-294-BA-MP. In addition, sublingual administration of ovalbumin combined with mucoadhesive maize-derived maltodextrin increased sublingual tolerance induction by targeting oral dendritic cells and ovalbumin-specific T cells in cervical and submaxillary lymph nodes. In conclusion, better understanding of specific immune responses to allergen at the level of the sublingual mucosa may lead to the development of new sublingual vaccines. In the future, such vaccines would incorporate Th1/Treg adjuvants, as well as mucoadhesive galenic formulations that target dendritic cells in the sublingual mucosa. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
The aim of the present study was to analyze the short-term relationship between pollen exposure and antiallergic drug consumption in the general population, taking into account confounding factors such as atmospheric pollution and meteorological parameters. Data on the daily consumption of antiallergic drug by individuals in the Clermont-Ferrand urban area from January 1 2000 through December 31 2001 and from January 1 2002 through December 31 2003, was obtained from the French health insurance database. An episode of allergic rhinoconjunctivitis (ARC) was defined as the association of an oral antihistamine and a local-acting antiallergic drug on the same prescription. The relationship between daily changes in atmospheric pollen concentration and daily changes in the number of treated ARC cases was analyzed using time series analysis. The results showed that the risk of treated ARC increased significantly with an interquartile increase in pollen concentration for grasses (5%, P < 0.001), hazel (7%, P < 0.02), birch (7%, P < 0.001) and ash (2%, P < 0.001). The effect was significant on the same day for all except the grasses, for which the risk lasted three days. Time series studies of antiallergic drug consumption may be useful for assessing the risk of exposure to pollens in an ambulatory population. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
Training in allergy exists in Moroccan medical schools, but it does not have the place that it should if we take into account the increased frequency of allergic diseases in Morocco (and elsewhere) and the increase in the demand for care that results. In our country, allergy is not recognized officially as a specialty and allergic patients are cared for either by pulmonary specialists or physicians with some training in allergy, or by generalists with a French medical school diploma or with an allergy diploma. There is no explicit allergy training program in the medical schools, but instead there are sessions on allergy presented in the different medical specialities from the second to the fifth years, in which immunology, asthma, eczema and urticaria, nasosinusoidal allergies, conjunctivitis and anaphylactic shock are considered. The amount of time devoted to teaching allergy does not exceed 30 h (which is 1.4% of the entire Curriculum). During classes in the third cycle, allergy is not clearly separated from other subjects; only the pneumology-pthisiology specialist course includes in-hospital training in allergy. Instruction is very limited in the other specialities. Moroccan medical specialists have the possibility to learn allergy on their own by enrolling in a university course in allergy and clinical immunology that is sponsored by the Department of Pulmonary Diseases in Casablanca. In regard to continued medical education, this can be done under the aegis of specialist scientific societies and associations. In conclusion, the teaching of allergy includes only an introduction but the number of hours devoted to this subject remains limited and it is time to think about the allergy course of the future. This teaching remains underrepresented in the third cycle which is devoted to clinical practice. This speciality must be developed, and it is now time to ask whether it should not be recognized officially. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
This review intends to summarise on the application of the basophil activation test (BAT) in the diagnostic management of anaesthesia-related allergy. The BAT relies upon flow cytometric quantification of alterations of particular basophilic activation markers. In the context of anaesthesia-related allergy the technique has been applied and proven reliable to diagnose IgE-mediated allergy from drugs (e.g., neuromuscular blocking agents, beta-lactam antibiotics), natural rubber latex, chlorhexidine, plasma expanders and dyes. Moreover, the technique has proven to be complementary to skin tests in the assessment of cross-reactivity and tailoring safe alternative regimens for future anaesthesia. (c) 2008 Elsevier Masson SAS. All rights reserved.
La prévalence de la rhinite pollinique a triplé en 25 ans dans la population française. Dans ce contexte, un travail de synthèse a été mené sur les associations entre les pollens et les effets sanitaires. Il comprend trois parties : les mesures d’exposition aux pollens, la relation entre pollens et effets sanitaires et la présentation des études épidémiologiques publiées. L’exposition aux pollens est toujours estimée à l’aide de mesures en extérieur et agrégées pour l’ensemble des populations étudiées. La relation entre les concentrations en allergènes et les manifestations cliniques est complexe et parfois difficile à interpréter du fait des variations liées à la sensibilité des individus, du décalage entre les concentrations en pollens et l’apparition des symptômes, des concentrations liées au seuil d’apparition des manifestations, des concentrations liées au seuil pour lequel les manifestations sont maximales, de la succession d’apparition des différents pollens, de la fréquente multisensibilisation des individus. De plus, l’étude de cette relation nécessite la prise en compte d’un certain nombre de facteur de confusion : facteurs météorologiques, aéroallergènes fongiques, polluants atmosphériques chimiques. La plupart des études épidémiologiques se sont intéressées aux liens entre les covariations temporelles à court terme (d’un jour à l’autre) d’indicateurs sanitaires mesurés soit à l’échelon individuel dans des populations spécifiques (étude de panel), soit à un niveau agrégé dans la population générale (étude écologique temporelle) et d’indicateurs d’exposition aux pollens. Une synthèse des études épidémiologiques mesurant les liens entre pollens et pollinoses saisonnières publiées entre 1978 et 1995 avait retenu 16 études seulement (15 études de panel et une étude écologique temporelle). Les conclusions de ce travail étaient que les résultats allaient dans le sens d’une association entre les niveaux de comptes polliniques et les pollinoses saisonnières, mais la quantification de l’effet et la forme de la relation dose–réponse ne pouvaient être clairement explicitées du fait de l’emploi de méthodes statistiques inappropriées et de la non-prise en compte des facteurs de confusion. Notre recherche actuelle a retenu neuf publications étudiant les effets à court terme des pollens (dont seulement deux études de panel). Leurs analyses confortent la relation existant entre les niveaux de comptes polliniques et des indicateurs sanitaires. Quelques publications permettent de quantifier l’effet à court terme des pollens, notamment avec les rhinoconjonctivites saisonnières et l’asthme.
Asthma is a very common respiratory disease in cats, being very similar to human asthma with regards to its clinical and pathological aspects. Allergic asthma is the form the most frequently diagnosed in humans and this is presumably the same for cats. The present study concerns 20 cats with clinically significant asthma, with appropriate radiological and broncho-alveolar cytological evidence for which an allergic workup had been carried out. The cats had a history of recurrent coughing episodes, wheezing and expiratory dyspnea for which regular oral or systemic corticotherapy was required. After these corticoids were stopped and replaced by inhaled corticoids, skin tests were done on 18 of the cats. The results showed sensitization to aeroallergens, mainly house dust mites, less often to pollen, in 15 of them. Avoidance of dry cat food resulted in remission of symptoms in three cats allergic to storage mites. Specific immunotherapy was prescribed for 12 cats. After 6-9 months of therapy, total remission of asthma symptoms was observed in eight (67%) of them. Four cats still required pharmacotherapy, including inhaled bronchodilator and corticoid 2-3 times per week. This study illustrates the role of an allergenic factor in feline asthma and demonstrates the advantage of a specific therapy, avoidance or specific immunotherapy. (C) 2008 Elsevier Masson SAS. Tous droits reserves.
The asthmatic patient is at risk of bronchospasm during anaesthesia. The risk increases in severe asthma. Uncontrolled asthma is the main risk factor. The preoperative evaluation of asthma control is therefore necessary and if possible the patient will be prepared with bronchodilators and steroids. Locoregional anaesthesia will always be preferred to a general anaesthesia during which endotracheal intubation can induce bronchospasm. Inhaled anaesthetics are well tolerated, in being bronchodilators. Ketamin and benzodiazepines can be used. Propofol and opioids are usually well tolerated in asthmatics. Among myorelaxants, these without histamine release effect will be preferred. During local anaesthesia, lidocain can be used. Its bronchodilator effects are considered. The preventive and a fortiori curative use of beta-2 agonists agents are the treatment of choice of perioperative bronchospasin, associated to steroids. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
Bilateral hypertrophy of the palatine tonsils can be either an acute or chronic a condition. Chronic hypertrophy is now more and more frequent, and it usually affects children of less than five years of age who otherwise may not have pharyngitis often. The etiology and pathogenesis of tonsillar hypertrophy are not clear. Two hypotheses are currently the most accepted: the first, the deleterious effects of pollution, and the second, inflammation in the upper airways. When ventilation is affected, particularly during sleep, corticoids are the recommended treatment for the acute form and tonsillectomy for the chronic form. It should be noted that that intervention has no immunoallergic consequence, even in very young infants. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
Here is the translation for the French Society of study of allergies of the reference document stemming from the World Organization of the Allergy (WAO) defining the doctor allergist. (C) 2008 Elsevier Masson SAS.
All asthma consensus statements recommend the use of a written action plan. Patients tend to have a positive perception regarding the use of action plans for asthma. They find that action plans are useful for the managernent of their asthma. Nevertheless, an action plan should not be viewed as the only element in self-management strategy. It is usually part of a multifaceted intervention, including therapeutic education sessions, medical review and prescription of medications. A recent meta-analysis reported a positive effect of the use of written action plans. It is agreed that a written action plan should be tailored to each individual patient and to the type and severity of his asthma. Still, the precise elements of action plans that are responsible for their benefit have not yet been clearly identified. However, considering the different action plans that have been published, it would appear reasonable to build on prior experience and adopt a three-step approach, such as a sequence of stoplight colours, as a means to compare one action plan with others. (C) 2008 Elsevier Masson SAS. Tons droits reserves.
Case report: In a 16-year-old teenager hospitalized with a severe asthma attack, the diagonosis of severe asthma associated to allergy and current tobacco smoke and allergen exposure is confirmed. Despite the use of high dose of inhaled antiasthma medication, the disease remains uncontrolled and anti-IgE, omalizumab treatment is started. After few weeks, respiratory symptoms and function dramatically improve.Conclusion: Severe asthma must be readily diagnosed in order to adapt treatment and avoid fatal outcome or respiratory disability. (C) 2008 Elsevier Masson SAS.
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. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
To date, neither in vitro nor in vivo tests can establish with reliability the diagnosis of food allergy. The availability of recombinant allergens (RA) has led to improvement in the standardization of allergenic extracts and enrichment of natural extracts, resulting in more sensitive screening tests. These biotechnological advances facilitate the diagnostic approach which now rests on an individual reaction profile (component resolved diagnosis) with well-characterized allergens classified on a molecular basis. Development of diagnostic tests using RA or peptides expressing some distinctive epitopes of interest may improve the prediction of severe and/or persistent food allergies and guide the choice of the therapeutic measures that follow. (C) 2008 Elsevier Masson SAS. Tous droits reserves.
Allergens of plant and animal foods and pollen belong to a highly restricted number of protein families. The AllFam Database (http://www.meduniwien.ac.at/allergens/allfam/) provides regularly updated lists of protein families that contain allergens. At present, 2% of the 9318 protein families defined by the Pfam Database (http://pfam.sanger.ac.uk/) contain allergens. Related protein families can be grouped into superfamilies placing allergenic proteins in an evolutionary context. With the exception of the prolamin superfamily, allergenic plant proteins are found in few member families of their respective superfamilies. This might indicate that allergenicity emerged rather infrequently in a very limited number of protein families. Moreover, most members of a given protein family seem to be non-allergenic. In contrast to plant allergens, the allergenicity of animal food allergens seems to be dependent on the degree of identity to a human homologue. The closer a potential animal allergen is to a human protein, the less likely it is to act as allergen.
Some skin diseases require emergency medical intervention when they are life-threatening or when the eruption is spectacular and brutal and the patient has an elevated temperature. We will discuss the clinical presentations of these conditions, excluding cutaneous drugs eruptions. Patients with severe atopic dermatitis may require brief hospitalisation if their eczema is generalized, refractory to classical therapy, or there are infectious complications, as in the Kaposi-Juliusberg syndrome when the condition is associated with a secondary herpetic infection. Acute urticaria and angioedema are frequent causes of emergency room-visits. They can be the result of drug allergy, food allergy, allergy to stinging insects or contact urticaria. However, the cause is not always identified, even after a complete allergy work-up. Some cases of contact eczema are spectacular, in particular when the face is severely oedematous. Paraphenylenediamine, topical corticosteroids and topical non-steroidal anti- inflammatory drugs are often the cause of severe delayed-type hypersensitivity reactions. (c) 2008 Publie par Elsevier Masson SAS.
After three decades of practice in the field of allergy and clinical immunology, the increasing demand of patient care in allergy, together with the increased need for the training of medical generalists and specialists, have led us to develop a continuing medical education program in this field. This 24-month program, which now exists in Algiers, leads to certification in allergy/immunology. Professors from Algerian and foreign universities contribute to it. The majority of the allergy clinics which may be involved do not at present meet all the criteria of accreditation but it is anticipated that these criteria will be met in the coming years due in large part to this introductory program, together with the continuing medical education that has been available in our country since 1990. (c) 2008 Publie par Elsevier Masson SAS.
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. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
Allergens are capable of inducing specific IgE production and are recognized by IgE-receptor bearing cells, more particularly mast cells and basophils expressing Fc epsilon RI, the high affinity IgE receptor. However, they are also capable of directly stimulating certain cells of the bronchial mucosa, especially in a protease-dependent way. For example, many allergens such as those from house dust mites (Dermatophagoides pteronyssinus et Dermatophagoides farinae) have protease activity which is involved in the activation of bronchial epithelial cells, dendritic cells, T lymphocytes, B cells, eosinophils and airway smooth muscle cells. Overall, these activations amplify Th2 polarization, recruitment and activation of inflammatory cells, and airway smooth muscle cell contraction. Receptors such as the protease-activated receptor (PAR) have been involved in these functions. PAR-2, which has a role in protease-dependent activation by many allergens, is over-expressed in bronchial biopsies from asthmatic patients. Both phenomena may be involved in the development and amplification of allergic asthma. (c) 2008 Elsevier Masson SAS. Tous droits reserves.
