Friend bullied by teacher for skin depigmentation. Not been to school since, advice?

[nia]

Last Science lesson, one of my best friend was verbally abused by her teacher in front of the whole class. She is so quiet spoken, I honestly don't know her ethnic origin, except that she's British born. I think she is either Pakistani or Indian, and she comes from a Sikh background. She has very obvious depigmentation all over her body and in her hair, but I hardly ever notice it. On her face, her skin is white from her eyes up; the rest is brown. She is absolutely stunning though. No one in my year has ever bullied her for it (to my knowledge).
This new teacher literally asked her if she was wearing a mask, or if she was just screwing about with make up. He then told her to take her mask off. The poor girl just sat there for the rest of the lesson. Half the class reported it. The school has got the police involved too.
She didn't come into school today, nor is yesterday. I don't know what to do to help her confidence. I'm worried this will screw her body image up for life.