I share how I look like this.
This method may not be useful. Because I don't have the exact cause.
I modify the details of the diffuse map to express the details.
Add Skin Pattern Map + Blood Vessels Map + Mono tone Veins Map + Color tone Veins Map + Skin Detail Map of the default Bace Map (Doreen G8).
And add Modified Hands Map + Blanding Map for exposed skin (lower arm and lower legs).
Skin Pattern Map, Mono toins Map, and Skin Detail Map used the Skin Builder 3 for Genesis 3 Female.