A rare cause of chronic cough in children is reflex cough due to the otogenic reflex. In a minority of individuals, the external ear is innervated by a branch of the vagus nerve. In this case, irritants (eg, cerumen) can cause chronic cough, and removal of the irritants may improve the symptom.
So, otoscopy should never be left out in cases of cough and this possibility should be considered in the differentials.
Post Pic : A Normal Tympanic membrane (Left) on Otoscopy. Credits Med.uth.edu