If you have eczema, stay away from abrasive exfoliants and any kind of acid. They can make the problem much worse. You really need an emollient-rich moisturizer instead of a scrub. For someone with psoriasis, especially if it has formed a dry, silvery layer, try a cream or lotion containing salicylic or lactic acid. This creamy acid formula will help dissolve that thick surface more gently than a scratchy mechanical scrub. Plus, this allows emollients to get through that heavy scale. As with any exfoliant, once or twice a week is plenty. Exfoliant abuse can absolutely damage the skin's barrier function. It can actually create new psoriasis by traumatizing the skin, a phenomenon called koebnerization.
Find out more about this book:Simple Skin Beauty: Every Woman's Guide to a Lifetime of Healthy, Gorgeous Skin