A friend with a lingering dry cough started asking me questions about it. I, of course, because no one ever really does, had no definitive answers. I had recently been reading a chapter in Egan’s about interstitial lung disease and on taking down his history I learned he runs his own farm. So Portlandy!
“Hypersensitivity Pneumonitis – Farmer’s Lung!”
When you’re reading about zebras, everything looks like a zebra.
Hypersensitivity Pneumonitis is a general category of parenchymal inflammation as a response to inhaled organics and it can be caused by a multitude of biological compounds. There’s Coffee Worker’s Lung, Humidifier Lung, Hot tub lung, Cheese Washer’s lung, and my favorite Bird Fancier’s Lung because it’s fancy and involves birds. Each has its own pathogen at its root but the result is the same: Pneumonitis – swelling of the lung tissue. It is differentiated from pneumonia by the lack of an infectious agent.
Symptoms of pneumonitis include fever, chills. malaise. chest tightness, dyspnea, rash, headache and, of course, *drum roll* cough.
Radiographic features tend to show a diffuse micronodular interstitial pattern. Which is a technical term to “giant ugly mess”.
Farmer’s lung is a form of hypersensitivity pneumonitis that is most commonly caused by moldy hay, specifically the aspergillis that thrives there.
So I see a farmer, I see him cough, I just read about zebras, I see a zebra.
However, he had had a chest x-ray. It was clear.
No stripes. No zebra.
He had however, weeks ago. recovered from a chest cold. And this lingering, nagging, dry cough just would not subside.
And here’s where I came across something I hadn’t heard of. Possibly because it is recognized as an officially recognized condition in Europe but not the USA. Those sassy Europeans. They’re always ahead of us.
There doesn’t seem to be any hard evidence as to it’s cause but there is suggestion that the infection leaves behind something that upregulates the receptors that stimulate cough. Or it’s a continued immune response upregulating the cough receptors that lingers even after the virus is defeated.
It seems American’s are hopping on board with the term “postinfectious cough” and like typical cavalier Americans willy nilly inventing words because a hyphen is really hard to find on a keyboard, they went with “postinfectious” instead of “post-infectious”. This kind of portmanteau neologism is downright Shakespearean.
You can read about it here.
In the end, the answer, like always, is steroids. Inhaled if it’s not too bad. Oral prednisone if it’s so paroxysmal the patient can’t function.
Until I decided to go back to school for respiratory therapy, I thought love was the answer.
I was wrong. It’s steroids.
He’ll live. He’ll go back to his farm and tend to his zebras. I mean… horses.