DEAR DOCTOR K: As I've entered my 40s, the skin on my hands and face has started to change. What happens to our skin as we age?
DEAR READER: The shortest answer is that our skin gets old, like the rest of us. In fact, the three layers of skin get old in different ways. The skin's outermost layer, the epidermis, forms a protective physical barrier. The dermis, or middle layer, contains collagen and elastin, which provide strength, firmness and elasticity. It also contains blood vessels, immune cells, nerves and glands that produce sweat and oil.