If you have psoriasis, you know the struggle all too well - it's a relentless condition with no known cure, and can be extremely fickle to deal with.

On top of the pain, itchiness and irritation, the stigma of having a visual skin concern is real - and can impact sufferers' self-esteem.

Psoriasis is a condition where the body produces new skin cells in days, rather than weeks, without naturally sloughing them off in between. It causes "scaling skin with spontaneous relapses and remissions," explains Dr Sean Arendse from Flawless Rejuvenation.

The chronic condition is genetic, however stress can also be a trigger for people who develop it.

Those who have psoriasis will also know how hard it is to manage. While there are topical skincare and medications out there that can help control flare-ups, no treatment can cure them.

What you might not know, though, is just how common it is. According to the International Federation of Psoriasis Associations (IFPA), nearly three per cent of the world’s population has some form of psoriasis.

Here are four celebs who have documented their struggle with psoriasis, and in turn have helped raise awareness about this common, yet often misunderstood, condition.

LeAnn Rimes

In an essay for Glamour, LeAnn Rimes recently talked about her experience with psoriasis - a condition she's had since she was two years old.

She said, "When I was in public, I did I everything I could to hide it. Onstage I’d often wear two pairs of pantyhose or jeans. Underneath my shirt, my whole stomach would be covered in thick scales that would hurt and bleed. For so much of my life, I felt like I had to hide."

The singer said she's spent most of her life trying to treat her psoriasis with steroid creams, medications and experimental treatments, saying she felt like she was hiding and holding herself back.

But in honour of World Psoriasis Day, Rimes decided to pose nude and raise awareness of the autoimmune disease.

"I want to give a voice to what so many other people are going through. This is finally my time to be honest about what psoriasis is and what it looks like," she said.

"You know when you say something you've been holding in for so long, and it's such a sigh of relief? That's what these photos are to me. I needed this. My whole body - my mind, my spirit - needed this desperately," she said.

"When I look at these photos, I see so much more than my skin."

Kim Kardashian West

Through the years Kim Kardashian West has also shared her experience with psoriasis, after being diagnosed with it in 2011.

I think the time has come I start a medication for psoriasis. I’ve never seen it like this before and I can’t even cover it at this point. It’s taken over my body. Has anyone tried a medication for psoriasis & what kind works best? Need help ASAP!!!

— Kim Kardashian West (@KimKardashian)

In an episode ofKeeping Up With The Kardashians, the reality star talked about how the skin condition made her feel insecure and embarrassed.

"My career is doing ad campaigns and swim photo shoots. People don't understand the pressure on me to look perfect," Kardashian West said.

"When I gain a pound, it's in the headlines. Imagine what the tabloids would do to me if they saw all these spots."

However, Kardashian West has managed to make peace with her skin condition over the years, sharing her journey in an article on sister Kourtney's lifestyle websitePooshlast year.

She wrote, "I have learned to live with this spot without using any creams or medication - I just deal. Sometimes I cover it up and sometimes I don’t. It doesn’t really bother me."

In the article, she also offered some advice for people dealing with psoriasis, adding "If you have psoriasis, you can’t let it ruin your life or get the best of you."