The essential feature of pica is the eating of one or more nonnutritive, nonfood substances on a persistent basis over a period of at least 1 month (Criterion A) that is severe enough to warrant clinical attention. Typical substances ingested tend to vary with age and availability and might include paper, soap, cloth, hair, string, wool, soil, chalk, talcum powder, paint, gum, metal, pebbles, charcoal or coal, ash, clay, starch, or ice. The term nonfood is included because the di- agnosis of pica does not apply to ingestion of diet products that have minimal nutritional con- tent. There is typically no aversion to food in general. The eating of nonnutritive, nonfood substances must be developmentally inappropriate (Criterion B) and not part of a culturally supported or socially normative practice (Criterion C). A minimum age of 2 years is suggested for a pica diagnosis to exclude developmentally normal mouthing of objects by infants that re- sults in ingestion. The eating of nonnutritive, nonfood substances can be an associated feature of other mental disorders (e.g., intellectual disability [intellectual developmental disorder], autism spectrum disorder, schizophrenia). If the eating behavior occurs exclusively in the con- text of another mental disorder, a separate diagnosis of pica should be made only if the eating behavior is sufficiently severe to warrant additional clinical attention (Criterion D).
Although deficiencies in vitamins or minerals (e.g., zinc, iron) have been reported in some instances, often no specific biological abnormalities are found. In some cases, pica comes to clinical attention only following general medical complications (e.g., mechanical bowel problems; intestinal obstruction, such as that resulting from a bezoar; intestinal perfora- tion; infections such as toxoplasmosis and toxocariasis as a result of ingesting feces or dirt; poisoning, such as by ingestion of lead-based paint).
The prevalence of pica is unclear. Among individuals with intellectual disability, the prev- alence of pica appears to increase with the severity of the condition.
Onset of pica can occur in childhood, adolescence, or adulthood, although childhood onset is most commonly reported. Pica can occur in otherwise normally developing children, whereas in adults, it appears more likely to occur in the context of intellectual disability or other mental disorders. The eating of nonnutritive, nonfood substances may also manifest in pregnancy, when specific cravings (e.g., chalk or ice) might occur. The diagnosis of pica during pregnancy is only appropriate if such cravings lead to the ingestion of nonnutri- tive, nonfood substances to the extent that the eating of these substances poses potential medical risks. The course of the disorder can be protracted and can result in medical emer- gencies (e.g., intestinal obstruction, acute weight loss, poisoning). The disorder can poten- tially be fatal depending on substances ingested.
Environmental. Neglect, lack of supervision, and developmental delay can increase the risk for this condition.
In some populations, the eating of earth or other seemingly nonnutritive substances is believed to be of spiritual, medicinal, or other social value, or may be a culturally supported or socially normative practice. Such behavior does not warrant a diagnosis of pica (Criterion C).
Pica occurs in both males and females. It can occur in females during pregnancy; however, little is known about the course of pica in the postpartum period.
Abdominal ﬂat plate radiography, ultrasound, and other scanning methods may reveal obstructions related to pica. Blood tests and other laboratory tests can be used to ascertain levels of poisoning or the nature of infection.
Functional Consequences of Pica
Pica can significantly impair physical functioning, but it is rarely the sole cause of impair- ment in social functioning. Pica often occurs with other disorders associated with im- paired social functioning.