Causes of perichondritis include Trauma Insect bites Ear piercings through the cartilage Systemic inflammatory conditions (eg, vasculitides such as granulomatosis with polyangiitis, relapsing polychondritis) Incision of superficial infections of the pinna Because the cartilage's blood supply is provided by the perichondrium, separation of the perichondrium from both sides of the cartilage may lead to avascular necrosis and a deformed pinna (called cauliflower ear) in a matter of weeks.