Furuncles of the external auditory meatus usually occur in the cartilaginous portion. They consist of a boil that forms around a hair follicle in the skin of the meatus, associated with swelling, redness and pain of the affected area.
Because the skin is tightly bound to the underlying perichondrium, there is severe tension as the boil expands and disparity between the size of the boil and the amount of pain that it produces. The lack of room for expansion increases the tension, and if the boil arises from the anterior meatal wall, the pain is severely exacerbated by chewing. Moving the auricle or touching the tragus also cause severe pain.
Initially, the meatus may still be open, however, as the furuncle grows, it becomes occluded. The pre-auricular lymph node becomes palpable and tender to touch. There may be a yellowish serous exudate that
crusts around the furuncle. If the furuncle ruptures, frank pus is also noted.
Infection may also spread to the adjacent hair follicles and produce a diffuse otitis externa.
Boil (furuncle) occluding the right external auditory meatus.
Below, is a magnified picture of the furuncle. Note the complete occlusion of the external auditory meatus, the redness and the crusted exudate.