A new human embroidery craze, which sees people stitch patterns in their skin with a needle and thread, poses serious health risks and could be fatal, according to a top dermatologist.

Images have begun to circulate on social media of hands, arms and even lips stitched with cotton thread, ribbons and beads, leading to warnings from experts over the danger of self-harming among Chinese teenagers.

Wang Liuhui, director of dermatology at Fudan University Children's Hospital in Shanghai, said human embroidery could cause septicemia, which can be fatal.

"The disease occurs when a large amount of bacteria enters the blood system," she explained. "If not treated in time and properly, it will trigger multiple organ failure and shock.

"Our skin is not fully developed until about 18 years old and the body functions of metabolism, immunity and expelling toxins are not fully developed either. If children have skin allergies, they could suffer a series of allergic reactions," Wang added.

China Central Television reported on Sunday that some people had shared in forums hosted by internet company Baidu how to create skin patterns and make it less painful. The forums had been shut down by Tuesday.

According to some media reports, the craze was inspired by a Japanese cartoon, in which a teenage character has embroidery on his lips, arms and collarbone. The cartoon is not approved for broadcast on the Chinese mainland.

It comes just weeks after Chinese authorities alerted parents about an online "game" called Blue Whale that originated in Russia and encourages young people to harm themselves and eventually commit suicide over a period of 50 days.

Parents and educators have blamed the internet for influencing potentially dangerous trends among teenagers.

"What people used to do during their teenage years to show that they had grown up and that they were brave and special was to date someone or smoke. Now it has become more diverse and extreme because the young generation has access to more information on the internet," said Gu Qing, who is in charge of discipline at Shanghai Hanghua No 2 Middle School.

"Some freak shows spread on the internet are obviously negative for the teenagers, especially the 13- and 14-year-olds who are not mature enough to distinguish between right and wrong," she said.

Gu said the school holds a weekly session to instruct students how to treat online information, and encourages students to spot abnormal behaviors by their fellows and report it to teachers.

Zhong Yang, a counselor at the Shanghai Changning District Juvenile Mental Health Counseling Center, said that when teenagers feel unaccepted by a group of fellows or family members, or have a bitter experience, they will be more inclined to resort to self-mutilation, which is a way of venting negative feelings.

"We suggest parents spend enough time accompanying children during puberty, when they have to deal with changes both physically and mentally," she said.