A scratch or graze: a shallow wound on the skin caused by scraping against something.
自転車で転んで膝に擦り傷を作った。
I fell off my bike and got a scrape on my knee.
擦り傷はまず流水で洗ってから消毒してください。
For a scrape, first wash it under running water and then disinfect it.
子どもの服にはよく擦り傷の跡がつく。
Children's clothes often show marks from scrapes.