Kendall Jenner's dermatologist knows why you always get back acne.

It’s face acne’s little, underachieving cousin: Always in the background, well-hidden but just as pest-like. Back acne, or “bacne” as some like to call it, doesn’t often discriminate.

Men, women, young and old: it’s likely to appear on a back near, or on, you.

So what do we do about it? And how do we get rid of it?

Kendall Jenner’s got your back (pardon the pun). The supermodel and integral part of the Kardashian empire has spoke with relative candour in the past about how acne affected her youth in some of her most formative years.

“Where it really impacted me was how self-conscious I became about it,” Jenner said in a blog post on her website about her struggle with face acne.

A photo posted by Kendall (@kendalljenner) on Nov 30, 2016 at 3:04pm PST

“It completely ruined my self esteem. I wouldn’t even look at people when I talked to them. I felt like such an outcast; when I spoke, it was with my hand covering my face.”

Since then, Jenner has invested in a dermatologist to help clear things up, as well as an in-office laser treatment to keep breakouts at bay.

In a video shared on her website titled, Skin Savvy: Body Acne, Jenner introduces her doctor, Dr. Christie Kidd, to explain what is we can do to avoid getting ‘bacne’ in the future.

And it all comes down to how we are washing our hair. Dr. Kidd believes that for most of us, the last thing we do in the shower is rinse out our conditioner and it could be doing more harm than we think.

“Most of us, we wash our hair, we condition it, and when our conditioner is sitting, that’s when we wash our body, and then the last we do is rinse out our conditioner,” she says on the video.

“You need to wash and condition your hair first, rinse all your conditioner out and clip your hair up. And now wash your body.”

More than that, she suggests lathering body wash on your chest and back with your hands and not an abrasive brush or loofa, letting it sit while you wash the rest of your body. After that, rinse your entire body right before you hop out of the shower.

And that, she believes, is the key to avoid excessive acne on your back.