Difference... "cough-variant" asthma is diagnosed when the primary symptom of bronchospasm is cough as opposed to wheezing, the usual sign of bronchospasm. The bronchospasm is treated with bronchodilator and steroid inhalers and the cough is controlled with this therapy. The cough in " cough-variant" asthma responds to the usual treatment of asthma. Cough is the primary sign instead of wheezing.
Matter of degree/sx. Cva is what i would consider one of the mildest forms of asthma. In season one may cough intermittently without actually wheezing&be treated for a number of things before the tie in with asthma is realized. Often a simple steroid inhaler will stop the cough after a few days where abx & cough meds have no effect. Suspicion comes when you have kin with asthma.