The skin is the body's most visible and largest organ. It is an indication of the body's health and serves as a barrier against damage and infection. Skin diseases affect nearly everyone at some point in their lives, including infants, adolescents, teenagers, adults, and the elderly. If you have a severe problem with your skin, you should seek the advice of a dermatologist. Dermatology is the branch of medicine that deals with the diagnosis and treatment of skin, hair, and nail problems. Dermatologists are consulted for problems that go beyond the skin. Skin problems can hurt patients' self-esteem, cause discomfort that makes daily activities difficult, and, in severe cases, put their lives in jeopardy. Experimental studies are those in which researchers evaluate the effects of a new intervention. Most experimental investigations are randomized, which means that the subjects are assigned to groups by chance. An experiment, unlike a descriptive study, is one in which a treatment, technique, or program is introduced with the aim of observing a consequence or outcome.