When the poet lamented that there was "nothing to eat but food," he was obviously unaware of pica. Yet habitual eating of ordinarily indigestible, nonnutritious substances is as old as man. Lying in his sarcophagus with grass in his esophagus, King Nebuchadnezzar who "did eat grass as oxen" (Daniel 4:33) presents a notable biblical example. Dirt eating and other appetite aberrations have been recorded by Aetius (sixth century AD) and Avicenna (tenth century AD) and by a number of observers during the 19th and 20th centuries.
Substances comprising the pica collection are numerous and varied, but two—earth and ice—are of special medical interest because their ingestion is often associated with anemia. In both appetite perversions the anemia is that of iron deficiency characterized by hypochromia, microcytosis, and sideropenia. The two conditions, however, present differences in geographic distribution and ethnic background. And, according to some authorities, they may also differ in