What is cauliflower ear?

Cauliflower ear results from misshapen cartilage that forms after trauma to your ear. The medical term is auricular (or more specifically perichondrial) haematoma or seroma. Haematoma is a build up of blood whereas seroma is build up of serous fluid - like the fluid you get in a blister.

If not treated correctly the build-up can restrict blood supply which causes the cartilage to die and be replaced with a fibrous substance that calcifies and becomes permanent. This can occur from a single incident, usually blunt trauma or a shearing force from something being dragged over the ear, but it can gradually build up from repeated smaller traumas. The ear thickens and ends up hard and lumpy, somewhat resembling a cauliflower. It is also known colloquially as “wrestler’s ear”, “boxer’s ear”, “bat ear” and in Japan, “gyoza mimi - dumpling ear”! 

The initial treatment for a small bruises or contusions is ice, avoiding further injury and possibly over-the counter anti-inflammatories, but where there is a significant pocket of fluid, it should be drained as early as possible. Due to the risk of infection, it is recommended that you get the ear drained by a medical professional, but so long as you take precautions, this can be done at home.

Here is a guide for DIY draining:

If left untreated, the ear can get infected and become necrotic, or the inflammation can spread to the ear canal resulting in permanent hearing loss, tinnitus and predisposition to ear infections. 

The best way to deal with cauliflower ear is to avoid trauma to the ear in the first place by wearing appropriate ear guards or helmets and applying ice after every training session.

See this article for a more in-depth explanation: