This is only a suggestion. Whilst in Greece last year, my legs around the ankles and lower shin area turned red, and then a purple colour when agravated by heat. Day time was more irritable than the evening, although it was not of an itchy nature.
On our return to the UK it appeared to abate at first, but did come back a few times. I spoke to my Doctor regarding this, and he was not familar with the problem. Gave me some antibiotics and some cream to rub into the legs as they appeared to be tightening, like being stretched. Again not hurting.
Early part of this year, it became worse again, and by April I find it began to hurt very much. The skin on the ankles and lower shins seemed over stretched. I also noticed a reaction to my body, where certain areas would bloat, particularly my legs and lower torso.
I returned to my doctors, who could not find anything wrong. I went to another doctor and he diagnosed Cellulitis and infection caused to the legs, which can be caused by many things. I still have the problem although not anywhere near as painful, but legs seem to have thinned and the skin around the lower shin is tight.
Hopefully, you do not have the same problem, but I would go back to your doctors to make sure. This started on a holiday in Greece. I can remember also scratching my legs on some plants when out walking. However, I am not saying this is the problem.
Hope this helps.