While classic asthma has tell-tale wheezing and chest tightness, a chronic cough variant of asthma (CVA) usually presents only with cough. Its cause is not well understood, but CVA is clinically considered a variant type of asthma, a phase at the start of asthma pathogenesis, or a precursor of classic asthma.
A study recommends healthcare providers consider asthma a potential cause in patients with chronic cough. This is because asthma is a common condition frequently associated with cough.
Symptoms of Chronic Variant Asthma
Cough-variant asthma often has no other “classic” asthma symptoms. Still its most common symptom is a chronic cough, a symptom of various health conditions. Hence, without treatment, CVA may progress to become classic asthma or even uncontrolled asthma.
Symptoms of classic asthma may include:
- Shortness of breath
- Chest tightness
- Persistent cough
Despite CVA not causing significant problems, a chronic cough can affect your quality of life. It can lead to complications such as:
- sleep disruption/coughing at night
- exhaustion leading to absenteeism from work, etc
- urinary leakage and incontinence
Depression and anxiety (recent studies show CVA patients are on average more depressed and anxious than classic asthma outpatients)
Chronic Variant Asthma Versus “Classic” Asthma
A 2018 study concluded that CVA has the same pathophysiological features as classical asthma but in a mild form. The main pathophysiology of CVA is bronchial hyperreactivity.
A study examined 74 cough variant asthma patients and 115 classic asthma patients of varying severity. Particularly, 40 were prospectively observed for two years. Finally, it concluded that atopy is an important determinant of the development of wheezing in patients with CVA. Additionally, coughing annoys patients with CVA. Above all, physiologic abnormalities such as airflow limitation and airway responsiveness are more marked in classic asthma than in CVA.
In one five-year Longitudinal Study, researchers observed patients with chronic cough who developed classic cough variant asthma. Subsequently, they concluded longer duration of coughing might be an important factor that develops precursors of classical asthma in patients with CVA.
Another cross-sectional study reported mechanistic and phenotypic differences between CVA and classic asthma. This difference was observed during methacholine-induced bronchoconstriction. Moreover, the milder mechanistic impairment in patients with CVA may explain their lower frequency of wheezing. Finally, frequent coughing triggered by bronchoconstriction was predominantly associated with CVA and was unrelated to mechanistic variables.
While chronic cough is one of the most typical symptoms of CVA, other causes, conditions, or factors that cause a chronic cough can include:
- Chronic Obstructive Pulmonary Disease
- Upper respiratory infections, like sinus infections
- Postnasal drip
- Gastroesophageal reflux disease (GERD)
- Blood pressure medications
Several tests by the physician can help rule out these conditions when diagnosing CVA.
Diagnosis of Chronic Variant Asthma
Diagnosis of CVA can be quite challenging as it is usually characterized by a chronic cough. Chronic cough lasts more than four weeks in children and more than eight weeks in adults.
Therefore, one should always consult a doctor if they are experiencing an unexplained persistent cough, though it is wise to keep track of your cough and share the details with your doctor to avoid misdiagnosis.
A spirometry test is used by a healthcare professional to diagnose asthma. This test assesses how well your lungs work. If symptoms and test results are negative for asthma, the next step is a methacholine challenge test.
Ideally, when a person with asthma inhales methacholine, it triggers coughing and bronchial spasms. Therefore, a person with asthma will be more sensitive to methacholine than a healthy person causing lung function to drop during the test.
If a doctor strongly suspects CVA, they may skip the methacholine test and prescribe asthma treatments. Since CVA responds well to asthma treatment, a healthcare provider will be likely to diagnose CVA.You can also get some insights on how to know if you have asthma on our blog.
Treatment of CVA
Similar to asthma, treatment of CVA consists of a combination of drugs, including:
- Antihistamines/Allergy medication
- Inhaled corticosteroids or anti-inflammatory drugs that ease and prevent swelling in the airways
- A beta antagonist to prevent future asthma attacks.
- An antiasthmatic regimen of inhaled bronchodilators relaxes the muscles that tighten around the airways, leading them to open. They can act short-term or long-term depending on the severity of asthma
- preventive oral medications; Doctors often supplement inhalers with oral pills called leukotriene modifiers that relieve asthma symptoms for 24 hours
Tips to Prevent Asthma Attacks
Consistency in taking your medication is essential. Therefore, to make progress, you must make sure to take daily medications, and use your inhaler. Moreover, if you have coughing attacks, taking strong, short-acting medications is vital.
Often try to avoid known allergens or irritants that trigger your asthma such as, Dust, some insects, pollen, smoke, cold air, some exercises, etc. Especially, avoid smoking as it will trigger coughs and other respiratory illnesses
Uncontrolled asthma may have long-term consequences, thereby impacting your health. It is, therefore, necessary to seek medical attention as soon as you feel the symptoms.