A 25-year-old, healthy woman presents to your ofﬁce with a complaint of intermittent dyspnea and chest tightness. Her symptoms have beenintermittently recurring for the last 3 years. Over the last 2-3 months they have occurred more frequently and lasted longer. Her symptoms tend to be worse during the spring months. She denies any exercise-induced ornocturnal symptoms. Her father has a history of asthma. She works as computer programming and software developer. She has a roommate whomoved in 3 months ago with a dog. She is an occasional smoker and drinks socially. She denies any recreational drug use. On exam she is mildlydyspneic, has end-expiratory wheezing and her respiratory rate is 20.