I would hate to give you advice that could get you fired... but I would say grow em.
It's not about some cliche "stop caring about what other people think". The truth is, on your job you only owe them your professionalism, not your identity. I tie my dreadlocks down and maintain them so they are not a distraction, dresscode violation, or safety hazard (despite what ive said before). Many of my coworkers are disruptive due to social and workplace ettiques that eclipse my hairstyle.
I can't speak for tattoos or piercings, but If a company fires you because of that, then you are making the statement that your sense of self and diginity is worth more than money.