Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Phacomatosis pigmentovascularis ?
    ### Response:
    Phacomatosis pigmentovascularis (PPV) is a skin and blood vessel disorder that is present from birth. Common signs and symptoms include port wine stain and pigmentary lesions, such as melanocytic nevi or epidermal nevi. A variety of classification systems have been proposed for PPV, largely depending on what type of pigmentary lesion is present.
    