Patient description: The patient is a 15-year-old boy with asthma diagnosed a year ago. He presents with shortness of breath, chest tightening and cough. According to his mother, he didn't respond to the usual corticosteroid inhaler. He was admitted to the emergency department with diagnosis of severe asthma exacerbation. He is a candidate for general corticosteroid therapy. Spirometry revealed a forced expiratory volume in the first second (FEV1) of 60% of the predicted. His past medical history is non-significant. His family history is significant for asthma in his mother and his uncle. He used to be treated with combination of inhaled corticosteroids and Zafirlukast.

Clinical trial eligibility criteria: eligible ages (years): 15.0-60.0,  Asthma years of age at V1 Physician diagnosis of asthma and on prescribed asthma medication for at least the past 12 months at V1 Pre-bronchodilator FEV₁ greater than or equal to 75% predicted at V1 (to minimize the likelihood that variability in FEV₁ will preclude participants from having methacholine challenges in follow-up visits) Airways reactivity: Methacholine bronchial challenge with concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second (PC ₂₀) less than or equal to 8 mg/mL at V1 Stable asthma defined by no change in treatment, emergency department (ED) visit, hospitalization, or urgent health care visit for asthma for the 8 weeks prior to screening Non-smoker for more than 6 months and less than or equal to 10 pack-year history of smoking Ability and willingness to provide informed consent If receiving immunotherapy, must have had stable therapy for the 8 weeks prior to screening Spend a minimum of six hours per night in bed on average Willingness to sleep 5 days a week on average in the same place for the next 4 months  Weight less than or equal to 66 lbs. (30kg) at V1 BMI greater than or equal to 35 at V1 Acute respiratory illness in the month prior to screening Systemic corticosteroid therapy during the 3 months preceding screening History of sleep apnea by self-report High risk of sleep apnea as assessed by Multivariable Apnea Prediction (MAP) Index; high risk defined as probability that is equal to or greater than 20% Chronic diseases (other than asthma) that in the opinion of the investigator would interfere with participation in the trial or put the participant at risk by participation, e.g. non-skin cancer, chronic diseases of the lung (other than asthma), chronic heart diseases, endocrine diseases, liver, kidney or nervous system diseases, or immunodeficiency, any pre-existing conditions that may be contraindications to positive airway pressure including: severe bullous lung disease, pneumothorax, pathologically low blood pressure, dehydration, cerebrospinal fluid leak, recent cranial surgery, trauma, bypassed upper (supraglottic) airway Known sleep disorders that are currently under treatment by a sleep specialist Known intolerance to methacholine Absolute contraindications to methacholine that current use of beta-adrenergic blocking agent, heart attack or stroke in the last 3 months, uncontrolled hypertension, known aortic aneurysm Use of investigative drugs or intervention trials in the 30 days prior to screening or during the duration of the study