Most Asthma sufferers do not discover that there are different variants of asthma until their first attack. Cough variant asthma affects a small percentage of asthma sufferers. Often sufferers cough persistently for some time before they are properly diagnosed. Knowing the symptoms, cause and diagnosis of cough variant asthma helps patients to get diagnosed more quickly.SymptomsCough variant asthma does not present like other types of asthma. The primary symptom of cough variant asthma is a persistent dry cough which does not produce any phlegm or mucus. To be persistent, the cough must last for longer than six weeks. Attacks may occur during the day or during the night. Attacks are most commonly triggered by exercise, allergens or other common triggers for asthma. Often, sufferers with this type of asthma show none of the classic asthma symptoms that include wheezing or difficulty breathing.CauseCough variant asthma sufferers have a more sensitive cough reflex. However, the cause for these or other asthma symptoms remains unknown.Cough variant asthma often develops after triggers like prolonged exposure to cold air, allergens or an upper respiratory infection.Certain prescribed drugs like beta-blockers may bring on cough variant asthma symptoms. Certain over-the-counter drugs like aspirin may also trigger symptoms.DiagnosisCough variant asthma is difficult to diagnose as sufferers do not present normal asthma symptoms. The persistent cough associated with this type of asthma is often confused with bronchitis or other infections that produce dry coughs.The methacoline challenge test will positively identify cough variant asthma. However, this test is only performed by specialists. And the test only points to asthma once at least 20 percent of lung function is lost.More often, physicians prescribe asthma medication. If the symptoms subside, cough variant asthma is then positively diagnosed.Once properly diagnosed and treated with the proper asthma medication, the symptoms of cough variant asthma clear up in six to eight weeks. With proper management and education, cough variant asthma is a manageable disease. Those with a persistent, dry cough should seek medical treatment as soon as possible to identify cough variant asthma as the cause or to rule out other, more serious causes of persistent dry coughs in patients.