I am 70,male; have dry cough for the last 20-25 years. now anti-allergic dont work. i started dexamethazone tablets 1mg b.i.d, for last 2 months, it controlled. reducing to 1 mg daily, cough comes back. is 2 mg daily safe: covid- immunity fears?

Consult a pulmonologist for an accurate diagnosis and appropriate treatment. You may have an asthma equivalent problem without the wheezing component especially since dexamethasone has been effective. Inhalers may be recommended. . Studies like a chest ct scan or bronchoscopy may be recommended only if necessary.. 2 mgs dexamethasone isn't too heavy a dose.