Post Processing colour on photos

[Chebby]

Hi

I need help but not sure what the issue is, so posting here. When I edit and save as jpeg I end up with a red scratchy type of colouring. If you look on the arm of the model here will give you an idea of what I mean and the face and neck of the young woman with the flowers in the colourful photo. I do use editing software in my editing so don't know if that's the issue.

Cheers
Chris