Allergic inflammation as a cause of asthma is now well recognized. New methods of identification of allergen-specific IgE including improved in vitro technologies will require optimization of the lowest threshold for the detection of allergen-specific IgE in order to maximize sensitivity without loss of specificity, thus allowing for significant enhancement in a clinical setting for determination of allergen-specific IgE levels. New concepts of allergic inflammation include the recognition that significant histologic changes may occur even in the mildest allergic patients. Thus, early intervention with antiinflammatory therapies including corticosteroids or inhaled nedrocromil sodium appears clearly warranted based on these early pathological changes occurring in asthmatic individuals. Inhaled corticosteroids have been demonstrated to prevent pathological changes that otherwise occur in asthmatic patients whose sole therapy is use of inhaled B2 agonist. Corticosteroids have also been noted to be successful in the prevention of progression of pathological changes including the development of bronchiectasis in asthmatic patients with allergic bronchopulmonary fungoses. Allergen-specific immunotherapy may be successfully used in selective asthmatic patients allergic to pollen, dust mite, or certain mold allergens including Alternaria. Immunotherapy appears to be most useful in those patients who are allergic to one rather than many allergens and whose asthma is not associated with other significant precipitating factors such as chronic rhinosinusitis or aspirin sensitivity. The risk of systemic reactions to allergen immunotherapy in the asthmatic patient is significant.(ABSTRACT TRUNCATED AT 250 WORDS)