It is possible that the child's regular coughing at the same time every day could be a reaction to an allergen. Observing and noting down the specific activities and surroundings during the onset of the cough can help determine the possible cause. Trying an over-the-counter antihistamine for 5 to 10 days could also be a helpful step. If the symptoms persist or worsen after another week, it would be advisable to consult a doctor. A pharmacist can provide guidance on the appropriate product and dosage for the child.