Hermangiomas are non cancerous growths which usually grow on the skin or liver and are sometimes formed in the womb. There are two types, infantile hermangioma which grows after a child is born and congenital hermangioma which is present at birth.
They are normally harmless and disappear over time. My adult daughter had one on her back when she was born and although I can't remember how long it took to go there is no sign of it now. They are often referred to as strawberry birth marks due to their bright red colour and are made up of a group of blood vessels. Infantile hermangioma is more common in girls than boys.
I must admit to being alarmed at first because it seemed quite large but it started to shrink over time. They can become sore and crusty in certain cases but this is not usual and a trip to the doctor for medication can put it right. If the mark is in a place which causes disfiguration as on the face there are ways of treating it to make it less obvious.