Serious skin disorder involving the formation of blisters all over the body. Symptoms are large blisters and abrasions on all skin surfaces. The blisters are displaced if pressure is applied to an edge. The disorder continues to spread, so that after a period of years so much of the body is affected that the patient dies, but with modern medication this rarely occurs. The cause of pemphigus is the formation of immune substances against the material that normally holds together the cells of the skin. This weakens the skin to the extent that blisters can arise spontaneously. The illness can occur in young patients.