"Generally, there are environmental causes, such as the classic one with people who are exposed to moldy grain in silos or cotton fibers or certain other molds," he said. "Sometimes it's certain metals like beryllium."
These allergies can be dangerous and progressive, causing fibrosis of the lung, but usually it's only an acute disease, according to Blaser.
Doctors have long known about hypersensitivities to the brass dust in metal factories, he said.
"People always thought it was the metal itself, but maybe it's the mold," said Blaser. "It's either due to the metal, the mold or the action of the metal. All three are possibilities."
When American researchers examined the study subject's trombone, they found large number of microbacteria. After immersing his instrument in 91 percent isopropyl alcohol, the man saw his cough disappear and he has been symptom free for 20 months.
The association between disease and wind instruments, such as the trombone, trumpet, French horn, tuba and saxophone, seems counterintuitive. Anecdotally, wind instrument musicians have reported a greater lung capacity and even improved asthma because of their musical hobbies.
A 2009 study of orchestras in Croatia suggested that these musicians may be susceptible to chronic upper airway symptoms. Interestingly wind instrument playing may be associated with higher than expected lung function parameters.
Popular saxophone player Kenny Gcan reportedly hold a note for up to 20 minutes. Other wind artists practice so-called "circular breathing" that allows them to inhale and exhale simultaneously.
But professionals know the brass instrument, which can't be swabbed out like a woodwind, can harbor more than just breath.
Greg McCutcheon, a clarinet player and director of bands at Birdville Independent School District outside Fort Worth, Texas, tell his middle school musicians to rinse out their mouths before picking up their instruments.
"Whatever they eat before they play, even chewing gum, all the sugar gets blown into the instrument," said McCutcheon. "All that stuff gets stuck and is sitting there over time."
"In high school, the kids who are serious about playing brush their teeth before they play," he said.
A hot, humid climate like that in Texas can also wreak havoc with brass instruments, according to McCutcheon, 29. "When I taught in Houston, our schools would turn the air-conditioning off and a lot of the instruments got mold on them. It was gross. There was mold inside and out and we had to send them in for a 'chemical' repair."
Arthur Goodridge, a saxophone and flute player from Medford, Mass., said he, too, is not surprised some brass players develop HP.
The 61-year-old has been playing since he was in the fourth grade and said he would "definitely pay attention" to any symptoms of lung disease.
"My brother and sister and cousin played trombone," said Goodridge. "My cousin was never hospitalized, but he had some breathing problems that were never diagnosed when he was in his late 30s."
Goodridge, who composed a tribute to Miles Davis that was performed by renowned jazz trumpeter Tiger Okoshi, cleans his mouthpiece every day and his instrument after each use.
That, says one doctor, is prudent.
"This is a rare problem if a problem at all," said Dr. Myron Cohen, director of the University of North Carolina Center for Infectious Diseases. "Just clean the instruments."