Improper Shaving Technique
It is common for these cysts to form in shaved areas such as the face, neck, armpits, and the bikini area. This is a result of improper shaving technique with a blade. The reason is, that the hair end is left jagged slightly under the surface of the skin, which causes it to hang up. Using a dull razor promotes ingrown hair. A lot of men use petroleum-based face shaving gel or foam. It plugs the skin cells and hair follicles giving rise to ingrown hair.