Most people associate the word asthma with wheezing, breathlessness and a feeling of tightness in the chest. But there is a lesser known type of asthma called Cough Variant Asthma (CVA), in which the primary and sometimes only symptom is a persistent dry cough.
If you or a family member has been coughing for weeks with no apparent cause, it may be Cough Variant Asthma.
What Is Cough Variant Asthma?
Cough Variant Asthma is a form of asthma where the patient suffers from a chronic cough but without the usual wheezing associated with classical asthma. The symptoms of CVA can be subtle, so it is often missed or misdiagnosed as something else, such as acid reflux, postnasal drip or a lingering viral infection.
What are the signs of Cough Variant Asthma?
The hallmark symptom of CVA is a persistent dry cough that: • Duration > 8 weeks in adults or 4 weeks in children.
• In worst cases at night and early morning
• Can be brought on by exercise, cold air or respiratory infections
• Present without obvious wheezing or shortness of breath
Many patients don’t think of asthma because there is no wheezing, and many doctors look for other causes first.
What Causes Cough-Variant Asthma?
The triggers are much the same as those for ordinary asthma and may include:
1. Allergic reactions to pollen, including grass pollens such as Cynodon and Ischaemum
2. House-dust and dust-mites
3. Smoek and air pollution
4. Cold weather.
5. Respiratory viral illnesses
Those who have allergic rhinitis or seasonal allergies may be especially likely to develop Cough Variant Asthma.
How Is Cough Variant Asthma Diagnosed?
Diagnosing CVA can be tricky as the cough can mimic symptoms of other common conditions.
Doctors may suspect CVA if:
• A chronic cough that doesn’t respond to treatment for other causes
• Lung function tests suggest airway hyper-reactivity
• Cough responds to asthma medications
Investigations can involve:
1. Spirometry - evaluation of lung function and airway obstruction
2. Skin prick allergy test to identify the specific allergens that trigger a reaction
Early and accurate detection is needed to avoid the progression of the disease.
Treatment of Cough Variant Asthma
Treatment is based on the symptoms and triggers for the patient.
1. Avoid triggers The most important first step of long-term management is to identify and reduce exposure to known triggers.
2. Inhalers Inhaled corticosteroids are the mainstay of treatment. Medications such as budesonide and bronchodilators such as salbutamol can be very helpful.
3. Drugs to take by mouth Medicines such as montelukast and cetirizine may be helpful especially if an allergic component is involved.
4. Allergiebehandlung For patients known to be allergic, environmental control measures and allergen immunotherapy (allergy shots or drops placed under the tongue) may be considered as a way to get long-term relief.
Why early treatment is important
Untreated cough variant asthma progresses to classic asthma in about 30–40 % of adults.
Early diagnosis and adequate treatment can avoid the progression of the disease and improve significantly the quality of life.
A cough lasting more than 8 weeks should not be ignored. Talk to a specialist.
Kins Hospital Siliguri | www.kinshospital.com