If so, they should avoid such physical activity temporarily. Active and passive smoking Don't let anyone smoke around your coughing child. Remind the teenager who smokes that his cough may last weeks longer than it would without smoking. Common mistakes in treating cough Antihistamines, decongestants, and antipyretics are found in many cough syrups. There is no proof that these ingredients will help your child's cough, and the antihistamines may make your child sleepy.
Expectorants are of unproven value but harmless.
Milk does not need to be eliminated from the diet. Restricting it improves the cough only if your child is allergic to milk. Never stop breast-feeding because of a cough. Your child starts acting very sick. The cough lasts more than 3 weeks.