I don't know the state of your color calibration, but your problem sounds like a very common one, especially in digital photography, where cameras seem to want to make skin a bit on the ruddy-red side.
As hard as it may seem, the solution is to add a little green. Yes, green. That's what makes the red shift into the yellow direction.
I have two routines for this. In Camera Raw, I choose Red Hue in the Calibrate tab, slide it 7 or 8 units to the right. Then I slide Saturation down about the same amount under Saturation. I use this method so often that I keep these settings as part of my ACR default.
In Photoshop proper, the drill is similar: make a Hue/Saturation Adjustment layer, pick Red from the scroll-down, click once on the offending skin to refine the selection, then slide the Hue 3 or 4 units higher, and slide Saturation down a few units.
Hope this helps.
MB