|Café au lait marks||
Coffee-coloured birthmarks (known as café-au-lait spots or marks) on the skin are one of the first signs of NF1.
They are usually present at birth. Many people have one or two of these, but if more than six have developed by the time the child is five, Nf1 should be suspected. Café-au-lait spots can increase in size and number, and grow darker with age.
Definition from NHS Choices: Café-au-lait marks