Pain relief creams tend to work in one of four ways. Anti-inflammatory pain relief creams use soothing ingredients like arnica to reduce swelling. Meanwhile, counterirritating pain relief creams draw on ingredients like menthol and camphor to cool the skin. Some pain relief creams use salicylates, a type of non-steroidal anti-inflammatory drug (NSAID), to block a key enzyme in the inflammation process. And other pain relief creams numb the skin with a local anesthetic called lidocaine.