Ear cartilage is quite resistant to infection. The most common problems that occur with ear cartilage are traumatic, such as when boxers get hit over the ear, or when someone falls and has an accident, and you get a little swelling, or what we might call a hematoma, a collection of blood, in the ear cartilage.
If the ear cartilage were to get infected, it would become red and swollen, and it would be extremely painful to the touch. And the treatment for infected ear cartilage would be usually oral antibiotics.