Causes of perichondritis include
Insect bites
Ear piercings through the cartilage
Systemic inflammatory conditions (eg, vasculitides such as granulomatosis with polyangiitis Granulomatosis with Polyangiitis (GPA) Granulomatosis with polyangiitis is characterized by necrotizing granulomatous inflammation, small- and medium-sized vessel vasculitis, and focal necrotizing glomerulonephritis, often with crescent... read more
, relapsing polychondritis Relapsing Polychondritis Relapsing polychondritis is a rare, episodic, inflammatory, and destructive disorder involving primarily cartilage of the ear and nose but also potentially affecting the eyes, tracheobronchial... read more 
)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. Septic necrosis may also ensue, often with infection by gram-negative bacilli.
Symptoms include redness, pain, and swelling. The course of perichondritis can be indolent, recurrent, long-term, and destructive.
Treatment of Perichondritis of the Ear
Prompt oral antibiotic therapy, typically a fluoroquinolone, sometimes with an aminoglycoside plus a semisynthetic penicillin
For an abscess, prompt incision and drainage
Patients with diffuse inflammation of the entire pinna are given empiric antibiotics (eg, fluoroquinolones, which have good cartilage penetration) and often a systemic corticosteroid for its anti-inflammatory effects. Any foreign material (eg, ring, splinter) should be removed. If the etiology is not clearly infectious (eg, an infected piercing), patients should be evaluated for an inflammatory disorder ( see Overview of Vasculitis Overview of Vasculitis Vasculitis is inflammation of blood vessels, often with ischemia, necrosis, and organ inflammation. Vasculitis can affect any blood vessel—arteries, arterioles, veins, venules, or capillaries... read more 
).
Perichondrial abscesses are incised, and a drain is left in place for 24 to 72 hours. Systemic antibiotics are initiated with a fluoroquinolone or an aminoglycoside plus a semisynthetic penicillin. Subsequent antibiotic choice is guided by culture and sensitivity. Warm compresses may help. It is important to ensure that the perichondrium is reapproximated to the cartilage to maintain the blood supply to the cartilage and prevent necrosis. Reapproximation is ensured by inserting 1 or 2 mattress sutures through the entire thickness of the pinna, preferably through dental rolls on both sides of the pinna.
