If you're avoiding gluten for medical reasons, you should be careful when using exfoliating scrubs. Unlike most skin cleansing products that are applied topically, exfoliating scrubs cleanse by tearing off the stratum corneum (the outermost layer of your skin).
Needless to say, exfoliation is a pretty harsh process, regardless of your ability to cope with gluten. Minor cuts and abrasions are common, and skin irritation or inflammation often occurs after these skin cleansing sessions [source: American Academy of Dermatology]. However, there are a variety of gluten-free exfoliating products available (many of them are made from gluten-free oatmeal or cornmeal), though the lack of wheat's most famous protein will in no way decrease the harshness of the exfoliating process.
If, like many people using gluten-free skin care products, you have sensitive skin, you may want to stick with a less abrasive skin cleansing regimen, such as washing your face with a cleanser and following that with a moisturizer or skin cream. You won't get the immediate results of a deep exfoliating scrub, but using a cleanser regularly will help to slough off old skin over time and promote the growth of healthy new skin cells.