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): 18.0-45.0,  Asthma Age range 18-45 years, inclusive 2. FEV1 of at least 80% of predicted and forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio of at least 0.7 (without use of bronchodilator medications for 8 hours or long acting beta agonists for 24 hours), consistent with lung function of persons with no more than mild intermittent or mild persistent asthma. 3. Physician diagnosis of asthma 4. Positive methacholine inhalation challenge as performed in the separate screening protocol within the prior 12 months (defined as provocative concentration of methacholine of 10 mg/ml or less producing a 20% fall in FEV1 (PC20 methacholine) 5. Allergic sensitization to house dust mite (D. farinae) as confirmed by positive immediate skin prick test response 6. Negative pregnancy test for females who are not s/p hysterectomy with oophorectomy or who have been amenorrheic for 12 months or more. 7. Oxygen saturation of >94% and blood pressure within the following limits: (Systolic between 150-90 mmHg, Diastolic between 90-60 mmHg)  Clinical contraindications: 1. Any chronic medical condition considered by the PI as a contraindication to participation in the study including significant cardiovascular disease, diabetes, chronic renal disease, chronic thyroid disease, history of chronic infections or immunodeficiency. 2. Physician directed emergency treatment for an asthma exacerbation within the preceding 12 months. 3. Exacerbation of asthma more than 2x/week which could be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma. 4. Daily requirements for albuterol due to asthma symptoms (cough, wheeze, chest tightness) which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma (not to prophylactic use of albuterol prior to exercise). 5. Viral upper respiratory tract infection within 4 weeks of challenge. 6. Any acute infection requiring antibiotics within 6 weeks of exposure or fever of unknown origin within 6 weeks of challenge. 7. Severe asthma 8. Mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements. 9. Cigarette smoking >1 pack per month 10. Nighttime symptoms of cough or wheeze greater than 1x/week at baseline (not during a clearly recognized viral induced asthma exacerbation) which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma. 11. Allergy/sensitivity to study drugs or their formulations 12. Known hypersensitivity to methacholine or to other parasympathomimetic agents 13. History of intubation for asthma 14. Unwillingness to avoid coffee, tea, cola drinks, chocolate, or other foods containing caffeine after midnight on the days that methacholine challenge testing is to be performed. 15. Unwillingness to use reliable contraception if sexually active (IUD, birth control pills/patch, condoms). 2. Pregnancy or nursing a baby. Female volunteers will be asked to use effective birth control (stable regimen of hormonal contraceptive use for at least 3 months, intrauterine device placement, tubal ligation or endometrial ablation for at least 3 months through at least one week after study completion) and will provide a urine sample to test for pregnancy on study days. If the test is positive or the subject has reason to believe she may be pregnant, she will be dismissed from the study. Women who have been amenorrheic for 12 months may participate. Male volunteers will be asked to use condoms for the duration of the study through at least one week after study completion. 3. Usage of the following medications: 1. Use of systemic steroid therapy within the preceding 12 months for an asthma exacerbation. All use of systemic steroids in the last year will be reviewed by a study physician. 2. Subjects who are prescribed daily inhaled corticosteroids, cromolyn, or leukotriene inhibitors (Montelukast or Zafirlukast) will be required to discontinue these medications at least 2 weeks prior to their screening visit. 3. Use of daily theophylline within the past month. 4. Daily requirement for albuterol due to asthma symptoms (cough, wheeze, chest tightness) which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma. (Not to prophylactic use of albuterol prior to exercise). 5. Use of any immunosuppressant therapy within the preceding 12 months will be reviewed by the study physician. 6. Receipt of Live Attenuated Influenza Vaccine (LAIV), also known as FluMist®, or any other live viral vaccine within the prior 30 days, or any vaccine for at least 5 days 7. Use of beta blocking medications 8. Antihistamines in the 5 days prior to allergen challenge 9. Routine use of NSAIDs, including aspirin. 4. Physical/laboratory indications: 1. Abnormalities on lung auscultation 2. Temperature >37.8 C 3. Oxygen saturation of <94% 4. Systolic BP>150 mmHg or <90 mmHg or diastolic BP>90 mmHg or <60 mmHg 5. Inability or unwillingness of a participant to give written informed consent