There are a variety of ways the skin can experience burn injuries:

Q: Are birthmarks inherited?
A: No genetic connection has been established for birthmarks. Their appearance seems to be wholly random.

Q: Can birthmarks be explained by anything the mother did during pregnancy?
A: No connection whatsoever has been shown between birthmarks and anything the mother did during pregnancy.

Bringing up a child who looks different can be a significant, enduring challenge. Society places a great deal of emphasis on physical appearance. A visible birthmark can really make a child stand out in a crowd. Parents' reaction to others' treatment of their child can itself become an issue. Here are some ideas for coping:

Most birthmarks pose little or no problem since they fade away or are located in areas that are easy to hide. But, in the case of a large, obtrusive birthmark on the face, the individual can suffer very significantly indeed. In most cases, parental encouragement and support can be all that's needed to get through early childhood, but at the point of puberty the power of parents to help begins to wane. At that point, the perceptions of others becomes more significant.

Most birthmarks resolve on their own by simply fading away. Some of the larger, more severe ones that typically don't fade may respond to surgery or laser treatment, but these options should be approached cautiously since scarring may occur. There is a growing body of experience among dermatologists in treating birthmarks, and sophisticated new treatments combining laser therapy with other forms of light seem effective.

text here

It is not clear why some children have birthmarks and others do not. They are not inherited, and they are not caused by anything that happens to the mother during pregnancy.

There are two primary classes of birthmarks:

1. Red birthmarks, which are caused by extra blood vessels bunched together close to the skin surface and are called vascular birthmarks.
    
2. Pigmented birthmarks, which are caused by extra colour in the skin; the birthmark is a different colour from the rest of the skin.

• Stork Bite or Angel's Kisses. These tend to be pink, irregularly shaped and flat, less than three inches tall and wide, and usually found on the neck, head, or upper lip. Almost half of all newborns have one of these birthmarks, but there are no known health problems associated with them and they usually fade by the end of the first year.