Herpes, a vesicular affection of the skin. The bladders or vesicles of herpes vary in size from that of a pin's head to that of a split pea. They are usually distributed along the course of distribution of some nerve. In the common form known as "shingles," one of the cutaneous branches of an intercostal nerve is involved. Herpes also sometimes affects the lips, the neck, or one of the limbs. The eruption is sometimes attended by pain. After the lapse of a few days the bladders dry up, scabs are formed, and the disease is at an end.