Strawberry naevus is a kind of birthmark and is correctly called capillary haemangioma. It is caused by an abnormal growth of excessive blood vessels near the surface of skin. It is particularly common in Caucasian babies, particularly premature ones.

It usually appears in the first few weeks of life. It starts as a small, soft raised swelling, and can grow rapidly to become large and appear bright red, like a strawberry. It can occur anywhere on the skin but is more of a problem if it affects the face. In some cases it can protrude into nearby structures and interfere with breathing, speech, or visual development, and some may be so large that ulcers develop in them.

It usually reaches the final size in 3 - 9 months. This ranges from 1 to 25 cm, but most end up no bigger than a few cm across. After the growth phase, it usually remains intact for some time and then starts to regress in size slowly, even without treatment, to complete disappearance. Most will do so by the time the child reaches the age of 10. Occasionally a large strawberry naevus may leave behind some redundant marks.

Unless the growing naevus causes problems above, otherwise it is best to leave it, and wait for the natural regression to occur. Plastic surgery can be used if the skin is baggy after this.

When treatment is necessary, either medically in the cases of complications, or cosmetically in the cases of residual naevi in children old enough to feel the concern, it can be dealt with using a vascular laser as in telangiectasia.