What is a capillary malformation?

Today, the designation "capillary malformation" is widely used as a modern name for what was formerly called a nevus flammeus or port-wine stain. This new terminology, however, is inaccurate and ambiguous. There are at least nine different skin disorders fulfilling the criteria of a capillary malformation. Examples include nevus anemicus, cutis marmorata telangiectatica congenita, angiokeratoma circumscriptum, and several vascular lesions that, in the author's view, do not represent nevi, such as the nuchal or glabellar salmon patch and the cutaneous changes of Rendu-Osler disease. Hence, I propose that we should use "capillary malformation" as an umbrella term and not as a name for a specific cutaneous entity.