Revue francaise d'allergologie et d'immunologie clinique最新文献

Eosinophilic airway inflammation may be encountered in asthma and in non asthmatic eosinophilic bronchitis, which is a recently identified and common cause of chronic cough. Non asthmatic eosinophilic bronchitis may be differentiated from asthma by the absence of airflow limitation and of bronchial hyperreactiveness (potentially reflecting the different localization of mast cells within the airway wall). Diagnosis is based on the confirmation of eosinophilic airway inflammation, usually by induced sputum, in the absence of other causes of chronic cough or of radiological and lung function abnormality. The cough is generally improved by inhaled corticosteroids. The long-term outcome is still not known; non asthmatic eosinophilic bronchitis may lead to the onset of fixed airflow obstruction or asthma.

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.

Photosensitivity reactions group together reactions to sunlight, in which the pathophysiology involves the subject's immune system. Concerning exogenous photosensitivity reactions, the photosensitizing molecules responsible for their development have been definitively identified and the reactions are known to be a form of classical delayed hypersensitivity. Nevertheless, while the photosensitizing molecules in idiopathic light eruptions (e.g., polymorphic light eruptions and chronic actinic dermatitis) have not been identified, here, the mechanism is now most often considered to be a delayed hypersensitivity; they can also be IgE-dependent (e.g., solar urticaria). The diagnosis of photosensitivity reactions rests on the patient's history, the appearance of the lesions, their histology and the results of a photo-testing examination. During an exogenous photosensitivity reaction, its severity will depend on the intensity of the reaction, on its evolution to chronic actinic dermatitis or even more on the severity of the specific condition (e.g., polymorphous erythema and hypersensitivity syndrome). Solar urticaria is a serious condition because of its disabling character, the difficulty of treating it and, occasionally, by the existence of general signs or its association with systemic diseases. Hydroa vacciniform (vacciniform cold sores) and pruriginous lesions can lead to the development of particularly ugly scars. More disturbing, vacciniform cold sores can be associated with latent EBV infection and may be complicated by lymphoproliferative disorders involving natural killer cells or by haemolytic syndromes. Chronic actinic dermatitis is surely the most severe photosensitivity reaction because of the severity of the photosensitivity and the risk of its evolution to a lymphoproliferative disorder.

Cupressaceae pollen allergy has increased in the Mediterranean region in recent decades. This allergy constitutes one of the few causes of respiratory allergy of winter. With regards to its clinical manifestations, rhinitis and conjunctivitis are more frequent than asthma. There has been a progressive increase in the total and annual concentration of Cupressaceae pollen, the reasons for which are the parallel increase in the planting of these trees and the global hothouse effect with the resulting climate change, both of which increase the production of pollen and their concentration in the ambient air. The effectiveness and safety of specific immunotherapy for Cupressaceae allergy were demonstrated some years ago in double-blind, controlled studies in which either traditional subcutaneous therapy or sublingual therapy were used.