What causes skin break down in the elderly?

Age-Related. As a patient ages, the skin gets thinner and more susceptible to injury from very minor trauma. The best way to protect the skin is to moisturize it with thick creams daily to twice daily. Examples include eucerin cream and vaseline intensive cream.
Loss of collagen. 2 major factors influencing aging are genetics and environment. People are genetically programmed to age at a certain rate--this can be accelerated by constant sun exposure, smoking, and excessive drinking. The skin contains collagen which starts to deteriorate with time and thin out causing the skin to sag and wrinkle. Sun causes faster loss of collagen and damage to the skin.