Patient description: A 39-year-old man came to the clinic with cough and shortness of breath that was not relieved by his inhaler. He had these symptoms for 5 days during the past 2 weeks. He doubled his oral corticosteroids in the past week. He is a chef with a history of asthma for 3 years, suffering from frequent cough, wheezing, and shortness of breath and chest tightness. The symptoms become more bothersome within 1-2 hours of starting work every day and worsen throughout the work week. His symptoms improve within 1-2 hours outside the workplace. Spirometry was performed revealing a forced expiratory volume in the first second (FEV1) of 63% of the predicted. His past medical history is significant for seasonal allergic rhinitis in the summer. He doesn't smoke or use illicit drugs. His family history is significant for asthma in his father and sister. He currently uses inhaled corticosteroid (ICS) and fluticasone 500 mcg/salmeterol 50 mcg, one puff twice daily.

Clinical trial eligibility criteria: eligible ages (years): 6.0-17.0,  Asthma Participant(s) who meet all of the following are eligible for enrollment. Participant(s) may be reassessed if not initially eligible. Participants are eligible if they Have a primary place of residence in one of the pre-selected recruitment census tracts as outlined in the Inner City Asthma Consortium (ICAC) Manual of Procedures (MOP) Have a diagnosis of asthma made by a clinician >1 year prior to recruitment Have had at least 2 asthma exacerbations in the prior year, defined as a requirement for systemic corticosteroids and/or hospitalization Have the following requirement for asthma controller medication at the Screening and Enrollment Visit (Visit 0) according to the MEDS program[4, 2] For participants aged 6 to 11 years, treatment with at least fluticasone 250 mcg 1 puff twice daily or its equivalent For participants ages12 years and older, treatment with at least Advair 250/50 mcg 1 puff twice daily or its equivalent Have peripheral blood eosinophils >=150 per mm^3. Results can be obtained from participation in a previous ICAC study if obtained within 6 months of the Screening and Enrollment Visit (Visit 0) Currently a non-smoker Parent/legal guardian is willing to sign the written informed consent  Participant(s) who meet any of the following are not eligible for enrollment but may be reassessed. Participant(s) are ineligible if they Are currently pregnant or lactating Are currently receiving treatment with anti-immunoglobulin E (anti-IgE) therapy or have had anti-IgE therapy in the previous 3 months prior to screening Are currently receiving immunotherapy Have clinically significant abnormalities on complete blood count (CBC) with differential as determined by the site study clinician. Results can be obtained from participation in a previous ICAC study [including Registry for Asthma Characterization and Recruitment 2 (RACR2), NCT02513264} if obtained within the last 6 months of Visit 0 Was treated with systemic corticosteroids for any medical condition including an asthma exacerbation within the 2 weeks prior to Visit 0 Have had a cold in the previous 7 days Are currently participating in an asthma-related pharmaceutical study or intervention study or has participated in another asthma-related pharmaceutical study or intervention study in the previous 4 weeks prior to recruitment Are currently requiring greater than fluticasone 500 mcg bid plus long-acting beta agonist (LABA) 1 puff twice daily or its equivalent and\or individuals using oral corticosteroids daily or every other day at Visit 0. Participants who meet any of the following are not eligible for enrollment and may not be reassessed. Participants are ineligible if they Have any medical illnesses that in the opinion of the investigators would a.) increase the risk the participant would incur by participating in the study, b.) interfere with the measured outcomes of the study, or c.) interfere with the performance of the study procedures. Examples of such diseases are: phenylketonuria, cystic fibrosis, bronchiectasis, Type 1 diabetes, hemophilia, Von Willebrands disease, sickle cell disease, cerebral palsy, rheumatoid arthritis, lupus, psoriasis, hyperimmunoglobulin E syndrome, parasite infections, Wiskott-Aldrich syndrome, or allergic bronchopulmonary aspergillosis