Diseases and Disorder of the Skin
Any component of the skin can become involved in a variety of different diseases. The skin can often provide doctors with clues about the health of the body, since many diseases that affect other organ systems are evident as telltale clues on the skin. For example, a rash, such as that typical of measles or chicken pox , can indicate an infection that affects the whole body. A blue tinge to the skin, called cyanosis, means that the body is not getting enough oxygen and can indicate heart failure. A yellow tinge to the skin, known as jaundice , signals that the liver is not working properly. Other diseases are specific to the skin itself. These disorders range from the merely annoying or distressing, such as acne , to the potentially life-threatening, such as skin cancer . In response to various triggering substances, or allergens, immune cells known as mast cells in the skin may release a chemical called histamine. Other immune cells called T cells may directly damage the epidermis. T