Chronic cough explained: The fungal lung condition often mistaken for TB or asthma
A lingering cough is often blamed on asthma or past tuberculosis, but experts warn that a lesser-known fungal lung disease may be the real cause. This article explains aspergillosis, its common forms, who is most at risk, and why early diagnosis can prevent long-term lung damage.
A cough that lingers for weeks is often brushed off as asthma acting up or a leftover effect of tuberculosis. But in some cases, the real cause lies elsewhere and goes undetected for far too long.
“Prolonged presence of respiratory symptoms may occasionally suggest the presence of a rare yet serious fungal lung infection termed aspergillosis among patients with underlying lung ailments,” according to Dr Viny Kantroo, Senior Consultant in Respiratory, Critical Care, and Sleep Medicine at Indraprastha Apollo Hospitals.
What is aspergillosis, and why does it matter?
Aspergillus is a common fungus in our surroundings, and everyone breathes its spores every day without any complications. However, in people whose lungs are already damaged or weakened, such fungus spores can bring about several lung problems, which are designated by a collective term: aspergillosis.
Symptoms of the disease can vary greatly. For example, in some, there are mild allergic reactions in the airways, while in others, there is progressive damage in the lungs due to infection. Quick diagnosis is important in order to avoid discomfort in the long term.
“For patients, this means a cough or wheeze that looks like asthma or old tuberculosis may actually have a fungal origin,” explains Dr Kantroo. “Missing this diagnosis can allow symptoms to worsen over time.”
When asthma treatment does not work: Understanding ABPA
One form of aspergillosis, known as Allergic Bronchopulmonary Aspergillosis (ABPA), is more commonly seen in people with asthma or cystic fibrosis.
In ABPA, the immune system overreacts to Aspergillus spores, causing inflammation in the airways rather than a direct infection. Patients often experience persistent coughing, wheezing and thick mucus production.
“If asthma symptoms do not improve despite proper inhaler use and medication, ABPA should be ruled out early,” says Dr Kantroo. Undiagnosed ABPA can result in uncontrolled symptoms even when patients follow treatment correctly, leading to repeated flare-ups and lung damage over time.
The TB lookalike: Chronic pulmonary aspergillosis
Another condition that often escapes detection is Chronic Pulmonary Aspergillosis (CPA). This form typically affects people with structurally weakened lungs, most commonly after tuberculosis. Symptoms of CPA include long-standing cough, breathlessness, fatigue and occasional blood in the sputum. Because these features closely resemble TB, CPA is frequently misdiagnosed.
“Studies suggest that nearly half of patients with persistent respiratory symptoms after completing TB treatment may actually have CPA,” Dr Kantroo notes. “This highlights the importance of awareness and appropriate testing.”
How aspergillosis is diagnosed and treated
The early diagnosis of this illness plays an important part in anticipating complications. The sputum culture, blood test for Aspergillus antibodies, and chest x-ray may be recommended.
Treatment depends on the type of aspergillosis. Antifungal therapy, which could be long-term, lasting months or years, is typically necessary in the treatment of CPA. In contrast, treatment for ABPA primarily consists of corticosteroids to reduce inflammation in the airways, sometimes accompanied by antifungal therapy to limit the effects of fungi.
What patients should know
A cough should never be treated lightly, particularly if it does not respond to other forms of treatment, like asthma or tuberculosis. People suffering from asthma, bronchiectasis, or tuberculosis in the past seem to be at a high risk. Follow-up by a pulmonologist and more awareness about the condition can be helpful.
“Early recognition and appropriate treatment can improve quality of life and prevent long-term complications,” says Dr Kantroo. Sometimes, the problem is not what it seems. And when it comes to the lungs, looking beyond the usual suspects can be lifesaving.
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