because I noticed last week that dd had one on her neck. Thought it might have been some strange rash but had a closer look at her today and have realised it's a very large patch of skin that is coloured differently. Almost like a birthmark (she has olive skin, so it's a darker brown colour) but all around the front of her neck.
Obviously, I'll book a GP's appointment as it's definitely not a birthmark (i.e. has only materialised now and dd is 8) but has anyone else seen anything similar in their children?