utility texture create a red line around the nostrills.

The first thing that occurs to me is, maybe you can create a texture mask in Gimp or Photoshop to lay over that harsh line and tone it down. You can always try and fiddle around with the color ramp, but I guess that's where you'd loose detail. You can also modify that same texture that is giving you the harsh line, put some neutral gray over the line to tone it down or get rid of it entirely. You don't have to go to Photoshop or Gimp by the way, you can do it inside of Blender with texture paint. And in case you want to go back, maybe do a Save As of the texture before modifying it. Hope that helps. 

Looks like the utility texture being overlaid on to the skin base color is simply too strong. You have a few options to reduce its effects:

• Turn down the factor on the overlay node. This will reduce the effect of the overlaid texture globally which may not be what you want if you like how the other details are overlaid.
  
  
• "Erase" the offending part of the overlaid texture. If you paint 50% gray over that alar crease in the utility texture(s) it will have no effect. Of course this will remove the detail from the texture. You could duplicate the texture so it's non-destructive but it's arguably a waste of file space
  
  
• Paint a low-res mask texture. You could also paint a separate (low-res) texture as white and black to control the alar crease area. This way you're erasing the offending area of the overlaid texture while not altering the texture itself. Be sure to save the new mask texture to your hard drive if you go this route.