A 27-year-old who is terminally ill with melanoma has shared a photo of the cancerous mole that led to her diagnosis while urging her TikTok followers to have their skin checked.

Kassidy Pierson, who goes by the username @ohhkayypee on TikTok, often uses her account to update her followers on her health journey and to share details about the skin cancer that she has battled for more than six years.

When Pierson was 21, she was diagnosed with stage three cancer after a mole on her thigh was biopsied and found to be melanoma, a less common but more dangerous skin cancer that occurs when melanocytes grow out of control.

The following year, Pierson was diagnosed stage four, and now, after trying numerous treatments, is terminally ill and in hospice.

In a recent TikTok video, Pierson showed her followers the mole that she had on her inner thigh and described all of the symptoms that she noticed.

In the clip, Pierson began by explaining that many of her followers have asked to see the mole that was eventually diagnosed as melanoma.

“A lot of you have asked and I finally figured out the picture. This is what my mole looked like,” Pierson said as she showed a photo of her inner thigh. “It was bigger than a pencil eraser, it itched, it was dry, it bled when it was itchy. It had all the symptoms of [melanoma]. It was discoloured, it changed shapes.”

According to the American Cancer Society, the most important warning sign of melanoma is a new spot on the skin or a spot that is changing in size, shape or colour.

The organisation also notes that the “ABCDE rule is another guide to the usual signs of melanoma,” with A for asymmetry referring to whether both sides of mole match, B for border, when the edges are “irregular, ragged, notched, or blurred,” and C for colour referring to when it is “not the same all over and may include different shades of brown or black, or sometimes with patches of pink, red, white, or blue”.

Another symptom is size, with D standing for diameter, as most melanomas are larger than 6mm, or the size of a pencil eraser, and E for evolving, meaning the mole is “changing in size, shape, or colour”.

In the video, Pierson then explained that she originally noticed the mole was changing when she was 18 or 19, but that she didn’t have it checked by a doctor until she was 21, at which point she was diagnosed stage three.

“And then a year later I was diagnosed with stage four. Six and a half years later, I’m still stage four and I’m now terminally ill and on hospice,” Pierson said in the video. “So please go get your skin checked … at least yearly. If you see something suspicious, go get it checked sooner.”

Pierson’s video has since been viewed more than 1.5m times, with many of her followers thanking her for sharing the potentially life-saving reminder.

“I just went and got my skin checked because of you! Thank you!” one person commented under the video.

Another said: “Thank you for educating, you will save lives. I’m so sorry this is happening to you.”

“Thank you for this post because you might save someone else’s life. I think about you every day,” someone else wrote.

Speaking to BuzzFeed, Pierson said that she is now on end-of-life care because, despite the numerous treatments, the melanoma spread throughout her whole body and entered her brain.

“Unfortunately, as the melanoma has spread throughout my whole body, it has entered my brain with at least seven new tumors, if not more. Meaning that none of my treatments are working anymore, and unfortunately at this point they have nothing medically they can do. There are no treatments available for me,” she said.

In another video, Pierson explained to her followers that she doesn’t know how much longer she will survive, but that she expects she could die within six months.

However, she said that she is “not scared to die,” but that she is sad thinking about the moments she will miss.

“I am not scared to die, I am just sad. It is a very sad thing, for the moments that I will not be there for,” she said, before thanking her followers for the support.

The Independent has contacted Pierson for comment.