Okay, so now that we know that a port wine stain is, for lack of simpler words, a ‘proliferation’ of blood vessels along a nerve, I can tell you that recent research (which you’ll stumble across if you Google ‘port wine stain’) has determined that it is not hereditary.

The problem is simply a mutation that happens somewhere along the way as the fetus is developing. If it happens early (and therefore multiplies itself as the fetus grows), then you end up with a bigger, deeper, port wine stain. If it happens later in development, then you see a smaller, lighter port wine stain.

We’ve met people with varied port wine stains, from a little light-colored “Whatdidya spill there?” spot on a cheek, to Addy’s “Woah! What is On That Baby’s Face?” mask, to a half-bodied “Is that a purple tattoo?” job.

Again (and this is really important), these are not hemangiomas, they are not strawberries, and they will not go away on their own. But they are often all lumped together, since they are all ‘vascular malformations.’

Oddly enough (for a problem that’s not genetic), my third child Eloise was born with another “vascular malformation” – in this case, a hemangioma on her tushy. How do we know it’s a hemangioma, and not a port wine stain? Because that bright-pink little splotch is raised & bumpy; a port wine stain is dark and flat (to begin with). So, we can be reasonably assured that this pink little splotch, unlike a port wine stain, will eventually fade away as she grows.

In any case, I don’t care how long it takes that hemangioma to fade. It’s on your butt, sweetheart; I’m not paying to get that sucker to get lasered off.