Hi,
They could be an anomaly in the blood vessels, which are usually seen at birth.It is difficult to explain their appearance at this stage, unless it is associated with some auto-immune disorder affecting the blood vessels.
Capillary vascular malformations (telangiectatic naevi or nevi) are sometimes referred to as flat haemangiomas. However, these are not haemangiomas but are malformed dilated blood vessels in the skin. Lesions are non-cancerous and appear as blotches of red or purple skin discolouration on any part of the body. They are always present at birth, although they may become more obvious with time.
Since they are spreading ypu need to get it evaluated immediately. Perhaps the treatment modalities for hemangiomas may work in your case.
ref:http://dermnetnz.org/vascular/vascular-malformation.html
since it seems pretty wide spread, it sounds kind of like a port wine stain(pws). PWS can have raised parts and it seems to fit the description you gave. You can try going to a vascular birthmark clinic. Many of the larger well known hospitals have them.