A 20-year-old man comes to the physician complaining of cough, dyspnea on exertion, and nighttime awakenings with wheezing. His symptoms started 1 month ago after painting a room and using ammonia to clean the windows. He had mild shortness of breath and felt irritation and burning in his throat and nostrils afterwards. He did not seek further treatment at that time. He has a history of running marathons but is now limited to running 1 mile before he has to stop due to dyspnea and cough. He has no past medical history and does not use alcohol, tobacco, or illicit drugs.
Vital signs and physical examination are normal.
Office spirometry shows an FEV1 of 82% predicted, FVC 90% predicted, and FEV1/FVC 0.82. Chest x-ray is unremarkable.
Which of the following would be most helpful to establish the diagnosis?

Question

A 20-year-old man comes to the physician complaining of cough, dyspnea on exertion, and nighttime awakenings with wheezing.  His symptoms started 1 month ago after painting a room and using ammonia to clean the windows.  He had mild shortness of breath and felt irritation and burning in his throat and nostrils afterwards.  He did not seek further treatment at that time.  He has a history of running marathons but is now limited to running 1 mile before he has to stop due to dyspnea and cough.  He has no past medical history and does not use alcohol, tobacco, or illicit drugs.  
Vital signs and physical examination are normal. 
Office spirometry shows an FEV1 of 82% predicted, FVC 90% predicted, and FEV1/FVC 0.82.  Chest x-ray is unremarkable.
Which of the following would be most helpful to establish the diagnosis?

Quizplus · Accepted Answer

11ec193a_98e4_c657_853d_7ff653caa4ce_MD0002_00 Reactive airway dysfunction syndrome (RADS) is a form of occupational asthma that usually occurs in the context of workplace exposures. RADS is a subcategory of irritant-induced asthma; nonimmunologic asthma following a single high-dose exposure to an inhaled irritant is termed RADS. There are multiple diagnostic criteria for RADS (Table), and it has been observed after exposures to chlorine, ammonia, paint, diesel fumes, bleach, and other cleaning agents. Patients may show obstructive physiology on pulmonary function testing, and methacholine challenge is characteristically positive. Prognosis is variable in patients with RADS. Some patients may improve with inhaled glucocorticoids, but others respond poorly to typical asthma therapy. Many patients will suffer from persistent asthma-like symptoms (requiring inhaled glucocorticoids and bronchodilators), but others will have complete resolution of symptoms within 2 years. (Choices A and E) Pathologic changes in the airway have been described. However, video-assisted thoracoscopic biopsy and bronchoscopy with lavage are not needed to establish RADS diagnosis. (Choice B) A chest CT scan may be useful at the time of initial presentation to look for signs of chemical pneumonitis, but it is not likely to be helpful for a patient with subacute to chronic symptoms. (Choice D) Irritant exposures are not typically associated with cardiac diseases such as congestive heart failure or pulmonary hypertension which would be assessed with echocardiography. Educational objective: Reactive airway dysfunction syndrome is a nonimmune asthma-like illness that occurs after a single high-level exposure to a pulmonary irritant. Pulmonary function testing may show obstruction, and methacholine challenge testing can establish the diagnosis. __________ References: Irritant-induced asthma. (http://www.ncbi.nlm.nih.gov/pubmed/22327170)

A 20-Year-Old Man Comes to the Physician Complaining of Cough