Tingling Pimples around mouth

Since December/January I have been getting these small pimples around the sides of my mouth. They usually come in clusters and I get a burning/tingling sensation which usually means they are flaring up. Even when they aren't flaring up, they never fully go away. They look like normal pimples, most of them have whiteheads which I can pop. I've been to two doctors. One told me it was perioral dermatitis, the other said it was just a weird case of acne. But I've struggled with acne in the past and never has it tingles or lasted for so long. I was on oral medication for almost three months but it wasn't helping so i stopped using it. Around this time, I finally noticed the pimples clearing up and I was completely free of this problem for a few weeks. This past week though i'm noticing it coming back. Has anyone experienced this or can anyone offer insight as to what it might be? Thanks!