Please speak with your doctor
to see if a piercing is safe for you to get. Piercing your ear involves a needle going through the surface and through the tissue. It can introduce bacteria if it is not completed in a sterile place. Even without the pimples on your ear, piercing your ear, especially your cartilage come with risks such a infections and keloids. Since you have pimples in the area that you want to pierce, it is not recommended to have a piercing at this time. Pimples are caused by infections and contain pus. If you introduce a needle through that area, it can introduce the pus and bacteria into the cartilage and tissue which can lead to an infection. You will also have an ear ring, which is a foreign object in that area which can give a medium for the bacteria to grow on. For your pimples, you should make an appointment with a dermatologist
to have it examined to figure out the etiology of your pimples. It is usually not common to have pimples in that area so it may be another skin condition that needs attention. Once those issues resolve, you can reevaluate with your doctor to see if a piercing is safe to get. In the meantime, you can read more about risks of cartilage ear piercings to see if it is right for you.