Hello Cassie

I am glad you have got a diagnosis at long last and congratulations on making such an effort to get the ball rolling. I am glad you have such a caring GP too I think that is half the battle. A lot of healthy people suffer from LR especially when it's cold and it isn't regarded as a condition in the the sense that it needs treatment when it isn't associated with any any other disease because it doesn't cause any problems.
It can also be caused by blockages that can make the blood pool or run sluggishly such as the other ' sticky blood' conditions.
See
http://dermnetnz.org/vascular/livedo-vascularis.html
Remember that 'MCTD' is simply the name given to a particular set of symptoms with features of other CTD's, unlike for example measles and chickenpox which are quite separate diseases in their own right.
In fact there is some debate about whether 'MCTD' is a useful description/ diagnosis/ classification. It is handy to have names for various groups of patients who seem to share particular sets of symptoms. You will find you have many lupus type symptoms.
Many of us have features of another CTD along with our sort of lupus without having enough symptoms to get a diagnosis of that illness, depending on what antibodies we have and what sort of disease expression the antibodies take which is probably genetic in origin.
All the best
Clare