Children are whitening their skin with make-up to avoid being bullied or racially abused at school, according to charity NSPCC.
Its research suggested racial abuse and bullying of children had risen by one-fifth since 2015-16.
There were over 10,500 race hate crime offences against children across the UK in 2017-18 - an average of 29 a day.
A 10-year-old girl told NSPCC she "tried to make her face whiter" as others described her skin as "dirty".
The girl who called Childline to discuss her distress said: "My friends won't hang out with me anymore because people started asking why they were friends with someone who had dirty skin.
"I was born in the UK but bullies tell me to go back to my own country. I don't understand because I'm from the UK.
"I've tried to make my face whiter before using make up so that I can fit in. I just want to enjoy going to school."
While a 16-year-old girl from a Muslim background said: "People call me a terrorist and keep telling me to go back to where I came from.
"I dress in traditional Muslim clothes and I think it singles me out.
"I usually just put my head down and get on with it but it's getting to the point now where I genuinely feel like I might get attacked."
Research by the NSPCC suggested the number of hate crime offences recorded by police against under-18s went from 8,683 in 2015-16 to 9,752 in 2016-17.
The figure then rose to 10,571 in 2017-18.