Earwax

Background and Anatomy of the Ear Canal

The human ear canal is the only skin-lined cul-de-sac in the body. This S-shaped tube leads from the pinna to the tympanic membrane (eardrum) and has a diameter of a pencil (0.6 cm) and a length of two and one half cigarette butts (2.5 cm).   The outer half to two-thirds of the external ear canal is cartilaginous and the remaining one-third is bony.

Sensory innervation of the external ear canal arises from the mandibular branch of the trigeminal nerve, from the Arnold (branch of the vagus nerve) and from the posterior auricular branch of the facial nerve, as well as from the great auricular branch of the cervical plexus.  If you notice coughing as your ear canal is being irrigated, you are stimulating the vagus nerve.

Cerumen

One to two thousand cerumen (wax) producing glands line the outer third of the ear canal. Cerumen lubricates the skin of the ear canal and acts as a water repellent.  It discourages fungal and bacterial growth and traps dust and small foreign bodies keeping them from getting into the middle and inner ear.

Cerumen can be classified dry or wet.  The dry type is ash-like and flaky and ranges in color from light gray to brownish gray.  The wet type is divided into hard and soft.  The soft type is frequently found in children.  The hard type is most often observed in patients with impactions.