Dr. Matthew S. King, an assistant professor of pulmonary and critical care at Meharry Medical College in Nashville, Tennessee and team conducted a study in which 80 soldiers with difficulty breathing from Fort Campbell, Kentucky underwent physical exams that included tests to determine how well they were breathing and CT scans.
It turns out more than half (49) of the soldiers had lung biopsies when the exam couldn't find a reason for their breathing problems. Some of these soldiers had been exposed to a sulfur-mine fire in Iraq in 2003, however.
All the biopsies were abnormal, and the researchers diagnosed 38 soldiers with constrictive bronchiolitis. Constrictive bronchiolitis is a rare non-reversible lung disease in which the small airways in the lungs are compressed and narrowed by scar tissue or inflammation.
"Respiratory disorders are emerging as a major consequence of service in southwest Asia. In addition to our study, there have been studies showing increases in asthma, obstructive lung disease, allergic rhinitis and a general increase in reports of respiratory symptoms. This is a very rare condition in otherwise healthy individuals and is generally untreatable. We believe that it is caused by an inhalational exposure with which they have contact while in southwest Asia."
All those with constrictive bronchiolitis had normal chest X-rays, but about one fourth had nodules in their lungs that were related to their breathing problems, King's team reported.
"The evidence that an inhalational exposure is the likely underlying cause of these problems is mounting, and we owe it to our military to launch further investigations so that we may improve prevention, detection, and treatment of these deployment related respiratory diseases."
It is important to contrast this fibrotic extrinsic bronchiolar lesion with the inflammatory intrinsic bronchiolar lesion referred to as proliferative intraluminal bronchiolitis. This distinction is important to the clinician because the treatment and clinical outcome of these two lesions are markedly different.
The fibrotic constrictive lesion develops externally to the airway lumen, constricting the airway in a concentric manner with eventual obliteration of the lumen. The inflammatory proliferative lesion develops internally from the airway wall, filling the lumen with an inflammatory polypoid lesion of loose connective tissue or buds of granulation tissue.
Concentric bronchiolitis obliterans usually involves the mid-bronchiolar region, and the proliferative lesion usually involves the distal bronchioles, often extending into alveolar spaces and referred to as bronchiolitis obliterans organizing pneumonia (BOOP).
Dr. Michael Light, a professor of pulmonary medicine at the University of Miami Miller School of Medicine says the following:
"Pulmonary abnormalities probably are real after exposure to whatever it might be, from Middle Eastern deployments."
However, what about the local residents? Do they suffer from the same breathing problems?
"They're exposed to the same things, but we don't know if they get this problem. This is a wake-up call that there may be ways that can reduce the impact of these exposures."
Sources: The New England Journal of Medicine and The American College of Chest Physicians