Ok, I have a honeycomb pattern to the inner part of my left leg, below my knee. It isn't sore or itchy and I only noticed it a couple of weeks ago. I thought it was just a heat rash so i left it but it hasn't really left- it has just faded to a pale purple pattern now.
I decided to look it up today and found two options which both seem liable;
Idiopathic Livedo Reticularis
This is where the medium veins under the skin swell up. There is no certain cause (hence the word idiopathic) but it is usually triggered by exposure to the cold. This one makes sense as 3 months ago I moved to China and it was very hot within two days it had altered to being ridiculously cold and I think the sudden change in temperature shocked my system.
Erythema Ab Igne
This is similar to above but caused by overexposure to heat like laptops on thighs and hot water bottles.
Neither are to be worried about but if it becomes itchy, sore, ulcerus or you feel any lumps under the affected skin go to see a doctor straight away