User:DrSoumitra

Atypical Asthma (Cough Variant)

Cough is the most common complaint for which patients seek medical attention. Cough variant asthma (CVA) is a form of asthma, which presents solely with cough. CVA is one of the most common causes of chronic cough. More importantly, 30 to 40% of adult patients with CVA, unless adequately treated, may progress to classic asthma. CVA shares a number of pathophysiological features with classic asthma such as atopy, airway hyper-responsiveness, eosinophilic airway inflammation and various features of airway remodeling. Inhaled corticosteroids remain the most important form of treatment of CVA as they improve cough and reduce the risk of progression to classic asthma most likely through their prevention of airway remodeling and chronic airflow obstruction.￼



Cough variant asthma is a type of asthma that features a dry, nonproductive cough. There may be no traditional asthma symptoms, such as wheezing or shortness of breath. An ongoing cough is often the only symptom.

Cough variant asthma (CVA) is a common asthma variation in children.

Although CVA does not share other symptoms with regular asthma, it affects the body in several similar ways.

Indoor and outdoor allergens often trigger it, and it can increase the risk of developing other allergic conditions.

It also increases the sensitivity of the airways, and it narrows and swells the airways, which can disrupt air flow.

The lung changes that occur with CVA tends to be milder than those in classic asthma. However, studies suggest that 30 to 40 percent of adults with CVA will go on to develop classic asthma.

Being able to recognize the signs and symptoms of CVA and seeking appropriate treatment may prevent the onset of classic asthma.

The causes of CVA are not entirely understood, but an asthma cough often occurs with the following triggers:


 * exposure to allergens or irritants
 * having a cold or upper respiratory infection, such as sinusitis
 * using certain medications
 * exercise
 * changes in the weather

There is a clear link between asthma and allergies. As many as 80 percent of all people with asthma also have nasal allergies.

Allergies happen when the immune system overreacts to a substance that should not normally cause a reaction.

This suggests that the immune system is linked to CVA. It could also explain why CVA responds well to the medications that are effective in treating classic asthma.

Certain people may have a higher risk for developing CVA and other allergic diseases.

Risk factors can include:


 * having another allergic condition, such as eczema
 * having classic asthma
 * having a relative with asthma
 * being overweight
 * being a smoker or exposed to secondhand smoke
 * being exposed to environmental or occupational irritants

Knowing the risk factors for CVA and recognizing if a person has them may help a doctor to make a diagnosis.

CVA involves a chronic cough that does not produce mucus. This is often the only symptom.

A chronic cough is any cough that lasts more than 8 weeks in adults and more than 4 weeks in children.

Complications
CVA may not significantly affect lung function, but the chronic cough can be disruptive.

A cough from CVA can cause:


 * sleep disruption
 * exhaustion
 * vomiting
 * lightheadedness
 * urinary leakage and incontinence

The complications of CVA can disrupt a person’s quality of life, for example, through fatigue and absence from work.

Without treatment, CVA may progress to become classic asthma.

Classic asthma symptoms include the following, in addition to a cough:


 * difficulty breathing
 * chest tightness
 * shortness of breath
 * wheezing
 * asthma attacks, in which air cannot reach the lungs due to airway narrowing

The long-term complications of poorly controlled asthma can include decreased lung function and chronic obstructive pulmonary disease (COPD).

Serious and potentially life-threatening complications can include:


 * permanent narrowing of the bronchial tubes
 * pneumonia
 * collapsed lung
 * asthma attacks that don’t respond to treatment
 * lung failure

People should see a doctor if a cough lasts for more than 8 weeks with no known cause. Early treatment may prevent the development of complications or chronic asthma.

CVA can be difficult to diagnose since the only symptom is a chronic cough, and this can be a symptom of various health conditions.

However, a study of 131 cases of chronic cough found that 24 percent of these were due to CVA.

If any of the following symptoms develop, people should see a doctor sooner to rule out other conditions:


 * a fever of over 100°F
 * wheezing
 * shortness of breath
 * chest pain
 * coughing up blood
 * difficulty tolerating physical activity

Other conditions or factors that cause a chronic cough can include:


 * bronchitis
 * upper respiratory infections, like sinus infections
 * post nasal drip
 * allergies
 * acid reflux and GERD
 * blood pressure medications
 * COPD and chronic bronchitis

A number of tests can help rule out other conditions when diagnosing CVA.

Since people with CVA often have normal results in a chest X-ray or spirometry test, a doctor may carry out a methacholine challenge.

When a person with asthma inhales methacholine, it triggers coughing and bronchial spasms. A person with asthma will be more sensitive to methacholine than most people causing lung function to drop during the test.

If a doctor strongly suspects CVA, they may skip the methacholine test and prescribe asthma treatments to see if improvement occurs.

If cough symptoms improve with use of the asthma medications, but no other signs or symptoms of classic asthma are present, the provider will likely diagnose CVA.