A 69-year-old man presented with a 25-year history of gradual, asymptomatic thickening and wrinkling of the skin on the left side of his face. The physical examination showed hyperkeratosis with accentuated ridging, multiple open comedones, and areas of nodular elastosis... The patient reported that he had driven a delivery truck for 28 years. Ultraviolet A (UVA) rays transmit through window glass, penetrating the epidermis and upper layers of dermis. Chronic UVA exposure can result in thickening of the epidermis and stratum corneum, as well as destruction of elastic fibers. This photoaging effect of UVA is contrasted with photocarcinogenesis.My father was a traveling salesman, selling transformers to electrical utilities. I don't remember any facial asymmetry, but I do recall that his left elbow was always a darker color than the rest of his skin.
Photo and text from Jennifer R.S. Gordon, M.D., and Joaquin C. Brieva, M.D., published in the New England Journal of Medicine, via Neatorama.