The most common cause of cauliflower ear is
blunt trauma to the ear leading to a hematoma which, if left untreated, eventually heals to give the distinct appearance of cauliflower ear. Participating in
contact sports and
martial arts is a typical source of such trauma. The structure of the ear is supported by a cartilaginous scaffold consisting of the following distinct components: the helix,
antihelix,
concha,
tragus, and
antitragus. Joints, eyes, audiovestibular system, cardiovascular system, and respiratory tract can also be involved. The outer ear skin is tightly adherent to the perichondrium because there is almost no subcutaneous fat on the anterior of the ear. This leaves the perichondrium relatively exposed to damage from direct trauma and shear forces, created by a force pushing across the ear like a punch, and increasing the risk of hematoma formation. In an auricular
hematoma, blood accumulates between the
perichondrium and
cartilage. The hematoma mechanically obstructs blood flow from the perichondrium to the avascular cartilage. This lack of perfusion puts the cartilage at risk for becoming necrotic and/or infected. If left untreated, disorganized fibrosis and cartilage formation will occur around the aforementioned cartilaginous components. Consequently, the concave pinna fills with disorganized connective tissue. The cartilage then deforms and kinks, resulting in the distinctive appearance somewhat resembling a cauliflower. Rapid evacuation of the hematoma restores close contact between the cartilage and perichondrium, thereby reducing the likelihood of deformity by minimizing the
ischemia that would otherwise result from a remaining hematoma. Auricular hematoma most often occurs in the potential space between the helix and the
antihelix (scapha) and extends anteriorly into the fossa triangularis. Less frequently, the hematoma may form in the concha or the area in and around the external auditory
meatus. Importantly, an auricular hematoma can also occur on the posterior ear surface, or even both surfaces. Risk of necrotic tissue is greatest when both posterior and anterior surfaces are involved, although posterior surface involvement is less likely given its increased quantity of impact-dampening subcutaneous tissue. == Prevention ==