Definition
The bright red skin mark, colloquially known as a stork bite, occurs in many newborns and is caused by blood vessels in the skin dilating at this point. It is considered a subform of the port-wine stain (Naevus flammeus). It differs externally by its red color from harmless moles in babies.
It is often found in the baby’s neck, which is where the term “stork bite” comes from, and can reach a very variable size. It looks as if the stork held the baby at this point with its beak when it supposedly brought it to its parents. However, such a skin change can also occur in other parts of the body, for example in the breech area, in the face or head area or on the legs of the baby. The stork bite is a harmless phenomenon and usually disappears by itself within the first years of life. Permanent stork bites can – for cosmetic reasons – be removed by laser.
Causes
The stork bite is caused by an expansion of the smallest blood vessels in the skin – the capillaries. Due to the red color of the blood flowing through the capillaries, the stork bite appears in its bright red color. Since these are merely dilated vessels, the stork bite is located at the level of the skin and is not significantly raised. How the local vasodilatation occurs is not known for sure. Possibly it is a certain developmental defect in the maturation of the fetus.
Diagnosis
The diagnosis of a stork bite can usually be made by a pediatrician based on the characteristic clinical appearance of the skin change. The diagnosis is usually made shortly after birth, as the stork bite is then already present and is noticed in the hospital when the newborn is examined. If the doctor presses on the skin change with a transparent glass spatula, the blood can be squeezed out of the dilated skin vessels.
The stork bite thus blows off through local pressure. Due to this typical phenomenon and also the general frequency of stork bites, no further examinations are usually necessary to make a final diagnosis. The hemangioma (also known as blood sponge) should be considered for differential diagnosis. This is a benign tumor of the skin vessels, which can manifest itself in a clinically similar manner. In contrast to the stork bite, however, this tumor is usually slightly elevated above the skin level due to its proliferation.
