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): 12.0-69.0,  Asthma Asthmatic participants Males or females greater than or equal to 12 and less than 70 years of age Physician-diagnosed and investigator-confirmed stable asthma (excluding exercise induced asthma) Current treatment for asthma by a healthcare provider within the preceding twelve months: current asthma treatment defined as regular use of asthma medications. Asthma medications short and long acting adrenergic bronchodilators, bronchodilator combinations, inhaled anticholinergics, inhaled corticosteroids, cromolyn sodium and nedocromil, leukotriene modifiers and methylxanthines Stable asthma defined by no asthma exacerbation (emergency room visit, hospitalization, course of increased systemic steroids, or urgent health care visit for asthma) during the prior four weeks Forced expiratory volume at one second (FEV1) >70% predicted pre-bronchodilator Ability to provide screening and baseline information Ability and willingness to provide informed consent For women of childbearing potential: not pregnant, non-lactating, and agree to practice an adequate birth control method (abstinence, combination barrier and spermicide, or hormonal) for the duration of the study  Chronic oral steroid therapy (daily) Oral corticosteroid use within past 4 weeks Respiratory tract infection within past 4 weeks Chronic diseases (other than asthma) that in the opinion of the investigator would prevent participation in the trial or put the participant at risk by participation, e.g. chronic diseases of the lung (other than asthma), heart, liver, kidney, or nervous system, or immunodeficiency Known allergy to methacholine (for example, a previous bad reaction to methacholine) or to any other parasympathomimetic agents Current use of beta adrenergic blocking agent (a heart medicine) or a cholinesterase inhibitor (medicine used to treat myasthenia gravis or Alzheimer's disease) History of epilepsy, cardiovascular disease with bradycardia (slow heart beat), vagotonia (increased activity of the vagus nerve causing slow heart rate or low blood pressure), peptic ulcer disease, thyroid disease, or urinary tract obstruction History of cigarette smoking within the past 5 years or >10 pack years total Use of investigative drugs or intervention trials in the 30 days prior to enrollment or during the duration of the study Any condition or compliance issue which in the opinion of the investigator might interfere with participation Nonasthmatic control