The outer ear, the part that sticks out from the side of your head, is a structure made almost exclusively out of skin and cartilage. Cartilage is a stiff tissue that forms the distinctive shape of the nose or ears.

All cartilage has a thin layer of tissue around it, called perichondrium, which helps to provide nutrients to the cartilage. Infection of this thin tissue, termed perichondritis, is usually caused by trauma to the ear, either accidental or as a result of ear surgery, ear piercing (especially piercing of the cartilage), or contact sports.

Ear piercing through the cartilage is probably the most significant risk factor today. The most common bacteria causing this infection are called Pseudomonas aeruginosa.

While not a common infection, perichondritis may cause severe damage to the ear structure if it progresses to chondritis.

A painful, red ear is the most common symptom. At first the infection will look like cellulitis (a skin infection), but it rapidly progresses to involve the perichondrium. The redness usually surrounds the area of trauma, which may be an abrasion or laceration. There may also be fever, and -- in more severe cases -- fluid draining from the wound.

The diagnosis of perichondritis is usually made by history and physical exam. If there is a history of trauma to the ear and the ear is red and very tender, then the presumed diagnosis is perichondritis. There may be an abnormal change in the shape of the ear.

Treatment consists of antibiotics, either by mouth or directly into the blood stream through an intravenous line (IV). If there is a trapped collection of pus, surgery may be necessary to drain this fluid and remove any dead skin and cartilage.

If the diagnosis is made rapidly and antibiotics are started, full recovery is expected. In more advanced cases, when the infection involves the ear cartilage (chondritis), part of the ear may die and need to be surgically removed. This may result in the need for plastic surgery to restore the ear to its normal shape.

The main complication is extension of the infection into the cartilage of the ear, which would require removal of the damaged part and possibly cosmetic surgery to restore it.

If you suffer any trauma to your ear (a scratch, blow, or piercing) followed by the development of pain and redness over the stiff part of the ear, contact your health care provider for evaluation. You may need antibiotic treatment.

The best way to prevent this infection is to avoid ear piercing through the cartilage (not the ear lobe). Since this practice has become more popular, there has been a significant increase in the number of cases of perichondritis and chondritis.