A university student had to have her thumb amputated after developing a rare form of skin cancer from biting her nails.

Courtney Whithorn, 20, developed the nervous habit after being bullied at school and even bit her thumb nail clean off in 2014.

Despite 'freaking out' when her thumb started to turn black, the embarrassed teen kept it hidden from her friends and family for four years.

After eventually seeing a doctor, the psychology student discovered she had caused such trauma to her nail bed that it developed into a rare cancer, known as acral lentiginous subungual melanoma, and was diagnosed last July.

Despite undergoing multiple surgeries to remove the cancer, and try and save her thumb, Miss Whithorn, who lives in Brisbane, was forced to have the digit removed last week.

Although Miss Whithorn's doctor claimed her cancer was caused by her nail-biting habit, other medics disagree.

Dr Nis Sheth, consultant dermatologist & British Skin Foundation spokesperson told MailOnline: 'Whilst physical trauma has been associated with appearance of some skin cancers it’s highly unlikely that just biting nails would have led to this cancer.'

University student Courtney Whithorn had to have her thumb amputated after developing a rare form of skin cancer caused by biting her nails, which was triggered by being bullied

The stress and anxiety of being bullied caused Miss Whithorn to bite her nail bed clean off in 2014, which caused it to bleed profusely and turn black. Ashamed of her digit's appearance, Miss Whithorn hid her thumb (pictured before her diagnosis) for four years

After eventually going to a doctor, Miss Whithorn endured four surgeries to remove her tumour. Her thumb was eventually amputated due to the 'protocol' of treating her cancer

Miss Whithorn, who moved to Australia from Durham nine years ago, said: 'When I found out that biting my nail off was the cause of the cancer it shattered me.

'In my head I thought "I've done this to myself" but obviously I knew I shouldn't have that mentality. I couldn't believe it.

'When you think about how many kids bite their nails it's crazy it came to that.'

Although Miss Whithorn's nail appeared unhealthy for years, she kept its troubling appearance to herself.

She said: 'I bit the nail off and was obviously very self-conscious of how black it was.

'My hand was just constantly in a fist because I didn't want anyone to see it - not even my parents.

'I got a bit freaked out when my skin started to go black so I showed them for the first time this year.

'I can't even explain how self-conscious I was. I always had fake nails to hide it because it was so black. It was like paper whenever it grew back.'

When Miss Whithorn heard her cancer had been caused by her incessant nail biting, she initially blamed herself but has since realised she was not to blame for what happened

She eventually showed her thumb (pictured left after her first surgery) to her parents when the surrounding skin began to turn black. It never occurred to her the problem may be cancer

Although the thought of having her thumb amputated initially caused Miss Whithorn to 'freak out', she accepted it after learning her cancer was spreading (pictured after the amputation)

Miss Whithorn says that without the support of her boyfriend Tyson Donnelly (pictured) she is unsure how she would have made it through. The pair have been dating for four years and met after Mr Donnelly stood up for her at school when she was being bullied by her classmates

Miss Whithorn, who has deferred her studies while she recovers, finally visited a GP when her skin started to turn black and was referred to a plastic surgeon.

She said: 'I saw two plastic surgeons, and they were thinking to remove my nail bed to get rid of the black and then put a skin graft over it so at least it would be skin colour - I was happy with that.

'But before my first surgery to remove the nail bed, the doctors could tell something was wrong and decided to do a biopsy.

'I had to wait six week for the results. They were sent down to Sydney because they couldn't tell if the biopsy was malignant or benign.

'The result came back uncertain so the surgeons wanted to be safe and remove the whole nail bed and any blackness.

She added: 'They did more tests and when those results came back, I was told that it was a malignant melanoma which was very rare to have there, especially for someone my age and at that size.

'I was obviously very shocked I couldn't believe it at all. My mum just burst into tears.'

Despite the amputation being a success, Miss Whithorn (pictured after the surgery) has still not been given the all clear. Due to her cancer being rare, doctors are unable to tell the student what her prognosis is, which reduces her to tears every time it is mentioned

Miss Whithorn claims she was more afraid of the needles being used than the amputation itself

Although happy with how everything has turned out, Miss Whithorn is aware her cancer may return, which would force surgeons to 'keep cutting away until we get a clear result'

WHAT IS ACRAL LENTIGINOUS SUBUNGUAL? Acral lentiginous subungual melanoma is a form of skin cancer that develops on the palms of a person's hand, the soles of their feet or beneath their nail. It usually starts as a flat patch of discoloured skin, which can look like a stain, that slowly enlarges over months or years. Acral lentiginous subungual is a rare form of skin cancer and makes up less than one per cent of melanoma cases in fair-skinned people, who are more at risk. Its cause is unclear and not related to sun exposure. It is thought to be triggered by genetic mutations and usually affects people over 40. As the cancer grows, affected lesions can become several centimetres wide, and contain a variety of brown, black, blue-grey and red colours. Although smooth at first, the affected skin often becomes thick with an irregular surface, like a wart, and may bleed or ulcerate. Initial treatment usually involves cutting the lesion out. If the cancer has spread to the lymph nodes, these are often also removed. Source: DermNet NZ Advertisement

Miss Whithorn, who worked as a part-time receptionist, underwent two surgeries to remove her nail bed. A scan of her thumb's inner cells then suggested she was in the clear.

Yet, just one week later, specialists in Sydney told Miss Whithorn's surgeon the protocol for her form of cancer is amputation.

Miss Whithorn said: 'The plastic surgeon texted me saying that protocol for this melanoma, because it's so rare, is amputation.

'I had a panic attack at work, I read the word "amputation" and ran outside - I couldn't breathe. I freaked out - we'd never even spoken about amputation.

'We went and saw a melanoma specialist who also agreed that amputation was protocol because this was such a rare cancer.'

In an attempt to avoid amputating, her surgeon performed a third operation to remove any remaining malignant cells, however, that operation only confirmed the need to amputate.

Miss Whithorn said: 'I went to sleep not knowing whether or not I was going to wake up with my thumb.'

As well as operating on the digit, Miss Whithorn also had two lymph nodes removed to determine whether her cancer had spread.

She said: 'Because it had started to travel, the only option left was amputation.

'I wasn't scared going in for the amputation surgery - I was more nervous as I'm not a big fan of needles and stuff.'

Although happy now, Miss Whithorn describes her nail-biting habit as being a 'coping mechanism' while she was being bullied, with her often being unaware she was even doing it

Despite the amputation being a success, Miss Whithorn has still not been given the all clear.

She said: 'I'm still waiting for that set of results from the surgery last week and if it's clear then the surgeon watches me for the next five years, and I get regular scans and bloods.

'There's not enough research to say what the survival rate is or what the likelihood of it coming back is because we just don't know much about it. I've just cried every time it's been brought up.

'The location of the cancer in my thumb is unknown so if it still shows up then they're just going to have to keep cutting away until we get a clear result.'

Mr Donnelly told Miss Whithorn's bullies to 'shut up and leave her alone', which led to the pair sitting down for a chat. The couple have been together ever since

As well as her boyfriend's support, she thanks her family, who have been hit hard by the ordeal

At 16 years old, Miss Whithorn was the victim of school bulling, with the stress and anxiety of it triggering her intense nail biting.

She said: 'I've been a nail biter my whole life but in 2014 I was in year 11 in high school and I was chronically bullied.

'Rumours were started about me and if I sat with people at lunch they would completely ignore me like I didn't exist. Nail biting became a coping mechanism for me.

'I didn't even know I was biting my nails sometimes, it just happened. I sort of lost the feeling because I was doing it that often.

'I didn't even realise I'd bitten my whole thumb nail off until I saw how much blood was on my hand.

She added: 'It never really grew back the same. It only grew on one side of my thumb and I kept biting it off then eventually the bottom of my nail turned black.

'I just thought it was dead like when people bang their nails.'

Miss Whithorn, who thought her black nail was due to it being 'dead', such as when someone bangs their hand, worries about how many children are at risk due to their nail-biting habits

The now-confident student wishes she had stuck up for herself more at school and believes that could have prevented her whole ordeal. She encourages others to be more outspoken

After her classmate Tyson Donnelly, 20, stuck up for her during the intense bullying, he and Miss Whithorn became more than just friends and have been dating for four years.

Miss Whithorn said: 'Me and Tyson went to the same school. I wasn't really friends with him but he literally walked over to these girls who were talking about me and told them to shut up and leave me alone.

'He took me to sit with him and that's sort of how we met. We've been together since then so that's one good thing to come out of it.

'Without my boyfriend or family I honestly don't know how I would have got through all this.'

Miss Whithorn is speaking out to encourage people who are being bullied to tell someone, as well as for bullies to rethink their actions.

She said: 'I just wish I was as confident and as outspoken as I am now back then.

'If I could say anything it would be just stand up for yourself - absolutely no matter what it takes just stand up for yourself.

'Some people have asked me who my biggest hero is or biggest influencer is and now I say "me". Be your own person and be who you need to be.'