What is a port-wine birthmark?

Source: PubMed, NCBI / U.S. National Library of Medicine

Pediatric dermatologyPublished 1/1/2026Last synced 6/10/2026Status: syncedPMID: 41937274DOI: 10.1111/pde.70196

A port-wine birthmark is a flat, red or purple birthmark. It happens when tiny blood vessels in the skin don't form the way they should. You might also hear it called a port-wine stain, nevus flammeus, or capillary malformation.

Educational only

This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.