Clinical, Airway Inflammatory, and HRA Phenotypes, in Preschool Children With Acute Asthmatic Attack Presenting to the ED.

• airways inflammatory phenotype [ Time Frame: Within 24 hours from admission to the emergency department (ED) ] [ Designated as safety issue: No ]
  
• post attack bronchial hyperreactivity to adenosine 5'-monophosphate and to metacholine [ Time Frame: 1. Within 2 weeks of recruitment 2. After 3 moths from recruitment ] [ Designated as safety issue: No ]
  

• Relationship between post attack bronchial hyperreactivity to adenosine 5'-monophosphate and to metacholine and the response to treatment and cytologic phenotypes. [ Time Frame: 1. Within 3 weeks of recruitment 2. Beyond 3 moths from recruitment ] [ Designated as safety issue: No ]
  
• relationship between cytologic phenotypes and response to treatment. [ Time Frame: Within 3 months of recruitmant ] [ Designated as safety issue: No ]
  
• clinical phenotype [ Time Frame: whithin 1 month of presentation ] [ Designated as safety issue: No ]
  Clinical characteristics of the preschool children presenting to the ED with asthmatic attack will be compared to mormal controls recruited from ambulatory clinics at the same area.
  
  

Clinical, Airway Inflammatory, and HRA Phenotypes, in preschool children with acute asthmatic attack presenting to the ED.

Background:

Children under the age of 5 years have the highest hospitalization rate of asthma. The most common causes of acute exacerbations of asthma requiring urgent medical care are viral respiratory infections. Most of these children < 6 y old are not atopic.

The inflammatory response to these mostly viral-induced asthmatic attacks is not well characterized in the literature. Moreover it is not known whether different kind of inflammatory responses exist in this population and how this correlate to clinical outcomes and clinical phenotypes.

Therefore, the purpose of the present study is to:

Investigate the characterization of induced sputum cytology, bronchial hyper-responsiveness (BHR, and clinical phenotypes in preschool children with acute asthmatic attack presenting to the ED and whether there is correlation between specific sputum cytology and response to therapy.

and to investigate airways hyper-responsiveness (BHR)to adenosine 5'-monophosphate and to metacholine in pre school children 2-6 y old at 2 weeks and at 3 month following acute asthmatic exacerbation and look for correlation with response to treatment and sputum cytology.

Clinical phenotypes of this patient population will also be investigated.Clinical characteristics of the preschool children presenting to the ED with asthmatic attack will be compared to normal controls recruited from ambulatory clinics at the same area.