Hello and welcome to HCM
There are many reasons for dry skin
However, you have described certain specific areas where patches of dryness are present. There are couple of disorders which cause dryness of skin in patches. The next step is to visit a dermatologist
to find out the cause .
Mean while, you are take general measures to avoid the dryness and the pruritis
(itchiness) associated with it (if any).
You should use a mild soap for cleansing and bathing.
Do not scrub the skin too much as it causes loss of moisture.
Use good quantity of moisture in especially during winters.
Thanks and take care
Dr Shailja P Wahal