my daughter has one under her eye, but it's under her skin so no problems with ulceration etc. It looks a bit like a swollen bruise, so I get pretty sick of people saying "cor what a shiner", or "oh dear, she must have had a nasty fall"...Now I just say "it's a birthmark" before they've even finished - probably a bit rude, but I'm fed up of explaining it! She's being seen at the Great Ormond St dermatology clinic and they say that in 90% of cases they gradually disappear by the time they're 7. Fingers crossed...