Ingrown hair Symptoms and causes Mayo ClinicLump resulting from an ingrown hair is a painful ailment which demands adequate treatment. Such type of cyst forms when an ingrown hair becomes back within your epidermis, triggering irritation and potential infection. Treating an ingrown hair cyst caused by an strand properly may help ease unease and avoid further problems. If you're struggling with a cyst, seeking medical recommendations is advisable to address it properly and prevent any potential risks hinged on self-treatment.