Welcome to Healthcare Magic Are you a smoker. Smoking can increase chances of being allergic to smoke, dust causing dry cough. Antihistamine may give relief but will not help in long term. You may need further investigation like blood tests to rule out worm infection, fungal infection which can also cause allergic dry cough. Stop smoking if you do. Use handkerchief when you approach areas of smoke, pollution, anyone who is smoking, gardens to keep away from pollen as well. Consult your Doctor regarding blood tests which may be necessary to make diagnosis to the reason for cough. Do steam inhalation for relief. Yon can try cough suppressant syrups as well to reduce frequency and intensity of cough under medical supervision as well.