This is a hygienic issue unrelated to the earrings, 10k gold is an alloy metal, it will reach to sweat or dirt, everyone's skin is different and will react different. Personal hygiene can effect that especially in the back of the ear where one develops dirt and sweat. If you clean the earrings every once in a while it should resovle the issue Futhermore, we've sold thousands of these without that issue from other customers.