Scientists track severe asthma in kids to uncover hidden patterns

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Children with severe asthma: * Child aged 3 to 12 years * Asthmatic child who, despite treatment with a combination of inhaled corticosteroids (at least 800 mcg / day equivalent Beclomethasone) bronchodilators and long-acting or properly taken daily leukotriene or short acting nebulized bronchodilators (inhaler technique and compliance verified) presents one of the criteria following: * Persistence of symptoms or chronic use of bronchodilators short duration of action at least three times a week for at least 3 months * exacerbations in the previous year: * at least one care unit admission or continued resuscitation * at least two hospitalizations for acute severe asthma requiring IV therapy * at least 2 courses of oral corticosteroids for exacerbations * post BD FEV \<80% or UARS post BD\> 150% predicted * Signature of consent or the holder (s) of parental authority * Particular case of patients treated with Xolair® : Patients currently receiving Xolair® but who met the severity criteria of asthma, as described above, before the start of treatment with Xolair® are includable. Children with non-severe asthma: Inclusion Criteria * Child aged 3 to 12 years * Controlled without treatment or with low doses of inhaled corticosteroids (\<500 mg / day beclometasone equivalent) asthma * Child with normal EFR (Child over 4 years) * Child who did not have more severe exacerbation (assessed taking oral corticosteroids) in the previous year * Child not admitted in the previous year for asthma. * Signature of consent or the holder (s) of parental authority Exclusion Criteria: * Child with bronchopulmonary dysplasia * Child with severe sequelae of viral infections * Refusal of the child or parents Data collection for research and follow up of patients : tests carried out in the 3 months prior to inclusion are used Blood sample for DNA extraction and the biobank: for young children, sampling at least 4 to 5 ml on dry tubes for serum and 6 ml at least for DNA. These samples should be stored at room temperature, transported within 48 hours to biological resources (CRB) Necker E,fa,ts Malades.