Ingrown hairs, boils, or cysts? Appeared after shaving, caused by chafing from wearing pads. Feel like pea sized hard lumps beneath skin. More info in comments
This isn’t a pop but it’s what I find once a month between my big toe and the one next to it! Dead skin and sebum mixture, with hair coming out of it! About the size of a dime. Fun, huh?!
