Many people have birthmarks, and they usually appear on the skin before or shortly after birth. They do not pose a health risk, although large birthmarks can be rather disfiguring and can cause significant emotional upset later in life. In these cases, birthmark removal should be considered.

Occasionally, these birthmarks can be indicative of underlying health problems, so it is always worth consulting your doctor if you are worried.

The causes of pigmented birthmarks are unclear. Old wive’s tales would link the appearance of these brown patches with something the expectant mother either did or ate during pregnancy, or with damage to the child’s skin during childbirth. While this is not true, the exact reasons for their formation have not been established.

What we do know is that these patches are created when an excessive amount of pigmentation is produced in a localised area of the skin. This can produce different types of pigmented birthmarks:

Café au lait spots
These are usually oval in shape and brown in colour, although they can appear in different shapes and sizes anywhere on the body. Unless several large ones develop, they do not pose a threat to health.

Smaller and darker, moles are something most people will develop at some point. Larger moles should be monitored for changes in shape, size and colour.