How to treat infected cartilage piercing on the earlobe?

Good question-: It really depends on the extent of infection. If there is no pus or the area of the earlobe that is infected is small, then antibiotics (e.g. Cephalexin, doxycycline, trimethoprim-sulfamethoxazole) can treat it. However, if the infection is expansive or there is abscess formation, then it may require surgical intervention to drain or remove the most infected part, along with antibiotic therapy.