Cauliflower ear is an irreversible condition that occurs when the external portion of the ear is hit and develops a blood clot or other collection of fluid under the perichondrium. This separates the cartilage from the overlying perichondrium that supplies its nutrients, causing it to die and resulting in the formation of fibrous tissue in the overlying skin. As a result, the outer ear becomes permanently swollen and deformed, resembling a cauliflower.
The condition is common in martial arts such as Brazilian jiu-jitsu, wrestling, boxing, kickboxing, judo, sumo, or mixed martial arts, and in full-contact sports such as rugby league or rugby union.
People presenting with possible auricular hematoma often have additional injuries (for example, head/neck lacerations) due to the frequently traumatic causes of auricular hematoma. The ear itself is often tense, fluctuant, and tender with throbbing pain. However, because of potentially more remarkable injuries often associated with auricular hematoma, auricular hematoma can easily be overlooked without directed attention.
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. Most commonly coming from participating in grappling and combat sports such as Brazilian jiu-jitsu and mixed martial arts. The structure of the ear is supported by a cartilaginous scaffold consisting of the following distinct components: the helix, antihelix, concha, tragus, and antitragus. The skin that covers this cartilage is extremely thin with virtually no subcutaneous fat while also strongly attached to the perichondrium, which is richly vascularized to supply the avascular cartilage.
Cauliflower ear can also present in the setting of nontraumatic inflammatory injury of auricular connective tissue such as in relapsing polychondritis (RP), a rare rheumatologic disorder in which recurrent episodes of inflammation result in destruction of cartilage of the ears and nose.