Asthma: diagnosis, investigation and exploration strategy

ABSTRACT

The diagnosis of asthma is essentially based on clinical data occurrence of paroxystic episodes of dyspnea with wheezing. The onset of symptoms is often difficult to recognise in non-typical forms. In these cases the ventilatory function test response to histamin or acetylcholin can be used to demonstrate bronchial hyperresponsiveness. Besides chronic bronchitis and emphysema the main differential diagnoses may be regrouped in adults, within 6 etiologies cardio-vascular, tumoral, inflammatory and/or immunological, congenital and finally functionnal. In childhood other differential diagnoses may be added like bronchitis, tracheal or bronchial foreign body, cystic fibrosis and gastroesophageal reflux. Asthma is regarded as a syndrome with numerous etiologies allergic and non - allergic [viral infections, pollution, neuro-endocrine diseases, drugs and psychologic factors]. The investigations are based on chest X-ray, hemogram, ventilatory function tests and allergologic testing [skin tests and measurement of serum IgE and specific IgE]. The history of symptoms and skin tests would give the main results of allergolic investigations. The diagnosis of allergic asthma [allowing hyposensitization] is based on clinical data, positive skin tests and if needed, elevation of total and specific IgE. In adults, it is however necessary to perform bronchial provocation tests to demonstrate the allergic cause of asthma