Dear Colleagues
It never ceases to amaze me how some physicians are unwilling to accept a different opinion.
I was recently presented a patient in his 70s with a recent onset of fever and cough.
He was a known heavy smoker of some 50 years.
He denied contact with unwell persons, onsen/sento visits, contact with pets or previous tuberculosis exposure.
His history was remarkable for atrial fibrillation treated by ablation, congestive heart failure and chronic low back pain.
His medications included relatively standard treatments such as a beta-blocker, a loop diuretic, an aldosterone antagonist, a calcium channel anti arrhythmic agent, a direct oral anticoagulant, a non-steroidal anti-inflammatory drug, and a proton pump inhibitor.
I was informed that his physical examination was normal except for some fine lung crackles and digital clubbing.
A tentative diagnosis of an infective exacerbation of interstitial pneumonia was made and the patient was commenced on a penicillin derived antibiotic and corticosteroids.
An antibody screen revealed elevated sIL-2 receptor, KL-6 and SPD.
However, this was an over simplification. When I reviewed the case, the patient had been commenced on azithromycin by another hospital prior to admission to the current hospital.
Two prior chest computed tomography scans had not been reviewed by a radiologist. There was upper lobe posterior calcification that suggested post-primary tuberculosis.
Only one sputum examination was performed when THREE consecutive tests were required to check for acid-fast bacilli.
No interferon gamma release assay had been performed for quiescent tuberculosis.
When reviewing the patient (N95 masks were worn) he admitted to night sweats and 5 kg of weight loss prior to admission.
Moreover, on detailing his smoking habit, he switched to e-cigarettes 5 years ago. He had recently switched to a new brand around the time of developing his current symptoms.
This may not seem important, but there is a phenomenon called e-vaping associated lung injury (EVALI) which is due to the e-cigarette containing vitamin E. The vitamin E is sometimes included in some e-cigarette formulations.
Imaging of EVALI via computed tomography shows several patterns and it is therefore not possible to exclude this as a cause by imaging alone. The history is perhaps the most important indicator.
His physical examination was not normal at all. He had profound signs of chronic obstructive pulmonary disease including a barrel chest, a short trachea, hypertrophied sternocleidomastoid muscles and intercostal recession on inspiration. There were some mild scattered fine crackles. There was no evidence to suggest digital clubbing.
“Atypical” pneumonia had not been considered either. Hence, tests for Legionella, Chlamydophila or Mycoplasma had not been performed.
Hence, atypical pneumonia, EVALI, and post-primary tuberculosis (with possible reactivation) should have been on the differential diagnosis list.
When suggesting such additional disorders I was smirked at, as if it was not possible. This was by a junior doctor no less.
As a word of advice, never have early closure for a diagnosis. Never anchor to it when other information may suggest an alternative diagnosis.
As new information becomes available, it opens up new possibilities, perhaps never once considered.
Moreover, when there is a possibility of tuberculosis, further evaluations are warranted because if corticosteroids are indiscriminately used it could lead to reactivation and a disastrous outcome. Notwithstanding this, indiscriminate use of macrolide antibiotics can partially treat tuberculosis leading to negative smears and cultures. Be warned.
It’s time for physicians to take the history and physical examination seriously. Ignoring it at the over-reliance of imaging and non-specific lab data will lead the physician down the wrong diagnostic alleyway.
Soluble IL-2 receptor can be found in diseases such a lymphoma, sarcoidosis, tuberculosis, many solid cancers and in autoimmune diseases.
KL-6 is a marker for lung cancer developed in Japan. It is elevated in numerous diseases including interstitial pneumonia, sarcoidosis, tuberculosis, diabetes mellitus, allergic alveolitis, drug-induced pneumonitis, cryptogenic organising pneumonia, atypical pneumonia and so on. It is not specific to interstitial pneumonia alone.
These kinds of tests have been hijacked and many junior doctors consider that elevation of a particular marker equals one disease like a shortcut for the diagnosis. It does not mean that at all.
Although such tests may suggest particular diseases, they are by no means diagnostic.
As physicians, we need fine tune the diagnosis by focused history, physical examination and tests that provide a definitive diagnosis.
Whenever tuberculosis is considered be warned about rushing in with corticosteroids.
Think, think and think again.
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