U.S. Environmental Protection Agency. The skin is our interface with the environment and our bodies' first line of defense against infectious agents. Other papers in this volume illustrate very elegantly that UV-B irradiation has a selective, suppressive effect on immune system functioning. The function of this skin-associated lymphoid tissue is to respond to antigens that enter the body by way of the skin. This cutaneous immune surveillance system is vital to our ability to resist invasions by infectious agents.
Infectious diseases remain serious public health problems in the tropics and semitropics.
There are few experimental data to answer this important question. Analysis is further complicated because infection and disease outcome are affected, not only by the immunogenetic background of the host, but also by other environmental factors such as humidity, temperature, vector density and efficiency, concomitant infections, and host nutrition, to name but a few. Although the issue is very complex, a growing body of evidence suggests that UV-B irradiation can affect both pathogenesis and immunity in infectious diseases involving skin. The effect of ultraviolet radiation on the progression of skin disease has been the subject of investigation for almost a century. In the late 1880s, the Danish physician Niels Finsen began a study of the interaction of skin with sunlight.