If it is not in the original file, but is after editing, I'd be looking at my editing.

If using Clarity, the job of the filter to to bring detail out in images which may be soft, blurred or hazy. I sometimes see that blotchy effect when trying to bring out detail where there is dust / mist / fog in particular. Is it Clarity which is causing this? Different presets have different results. Have you tried the portrait presets in Clarity to see if that stops the blotches appearing on skin?

In your psd file, create a copy of the original image on a new layer. Apply Clarity to the new layer. Then by turning the eye on and off on the clarity layer, you will easily be able to compare the changes between the original and the edited image. That will let you know if Clarity is responsible. Do the same for every step in editing your image. Put each new effect on a new layer. That way you may be able to pick up what editing is causing the effect.

It is not just clarity which can cause this effect. Many filters designed to bring out detail in images will do the same. The answer is to mask out the areas you don't wanted extra detail bought out in. The masking can usually be done in the filtering software, or otherwise with a layer mask on the edited layer in Photoshop.