Rash is a general, nonspecific term that describes any visible skin outbreak. Rashes are very common in all ages, from infants to seniors, and nearly everyone will have some type of rash at some point in their life. There are a wide variety of medical diagnoses for skin rashes and many different causes. It is not possible to fully cover every type of rash in this type of article. Therefore, special mention has been given here to some of the most common types of rashes. A dermatologist is a medical provider who specializes in diseases of the skin and may need to be consulted for rashes that are difficult to diagnose and treat.