If it's worse in winter, then it may be due to dry skin, I wouldn't eliminate that source of the problem. Itching can be cause by many things, allergies to foods (gluten), chemicals (dyes), stress, etc.
Topically applied vitamin B-12 or vitamin D cream is known to relieve itching. Some people have good results with an Aloe Vera gel application.
Internal and external use of Extra Virgin Coconut Oil (unrefined), will help to hydrate the skin. Other supplements that may help are Omega 3s, Natural Vitamin E and Vitamin D3. Good luck, I hope you get some relief soon.
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