Pica

Pica is an eating disorder characterized by the eating of one or more non-nutritive, non-food substances on a persistent basis over a period of at least one month that is severe enough to warrant clinical attention.

• The prevalence of pica is unclear, but is higher in individuals with severe intellectual disability (up to 9 to 25% in institutionalized populations^[1]).^[2]
• Onset of pica can occur at any time, but childhood onset is most commonly reported.
• Pica occurs in both males and females equally.
  • It can occur also occur during pregnancy but little is known about its course.^[3]

• Typical substances ingested can vary with age and availability, including paper, soap, cloth, paint, gum, hair, chalk, string, wool, soil, talcum powder, metal, pebbles, charcoal or coal, starch, ash, clay, or ice.^[4]
• The term non-food is included because the diagnosis of pica does not apply to ingestion of diet products that have minimal nutritional content.

• Autism spectrum disorder, intellectual disability, schizophrenia, and obsessive-compulsive disorder.
• Pica can be associated with trichotillomania (hair-pulling disorder) and excoriation (skin-picking) disorder (e.g. - the hair or skin is typically ingested).
• Pica can also be associated with avoidant/restrictive food intake disorder (ARFID), most particularly in individuals with a strong sensory component to their presentation.

• Gastrointestinal problems (e.g. - mechanical bowel problems, intestinal obstruction, such as that resulting from a bezoar; intestinal perforation).^[5]
• Infections such as toxoplasmosis and toxocariasis can result from ingesting feces or dirt.^[6]
• Poisoning can occur from ingestion of lead-based paints.

• Neglect, lack of guardian supervision, and intellectual disability are risk factors.^[7]

• Some cultures have practices that include eating of earth and/or other non-nutritive substances for spiritual, medicinal, or social reasons. These are culturally supported or normative practices and do not warrant a diagnosis of pica.^[8]

Persistent eating of non-nutritive, non-food substances over a period of at least 1 month.

The eating of non-nutritive, non-food substances is inappropriate to the developmental level of the individual.

The eating behaviour is not part of a culturally supported or socially normative practice.

If the eating behaviour occurs in the context of another mental disorder (e.g. -intellectual disability, autism spectrum disorder, schizophrenia) or medical condition (including pregnancy), it is sufficiently severe to warrant additional clinical attention.

• There is typically no aversion to food in general.
• The eating of nonnutritive, nonfood substances must also be developmentally inappropriate for the individual's age (i.e. - normal mouthing of objects by infants that results in accidental ingestion is normal under age 2).

• The eating of non-nutritive, non-food substances may occur in pregnancy, when specific cravings (e.g. - chalk or ice) may occur.
  • The diagnosis of pica should only be made if the cravings lead to the ingestion of non-nutritive, non-food substances that lead to potential medical risks.^[9]

• Other mental disorders
  • Eating of non-nutritive, non-food substances can occur during the course of other mental disorders (e.g. - autism spectrum disorder, schizophrenia, Kleine-Levin syndrome). In these cases, pica should only be diagnosed if the behaviour is sufficiently persistent and severe to warrant additional clinical attention.
• Anorexia nervosa
  • Pica can usually be distinguished from the other feeding and eating disorders by the ingestion of non-nutritive, non-food substances. Some presentations of anorexia nervosa include ingestion of non-nutritive, non-food substances (e.g. - paper tissues) to control appetite. In these cases, when the eating of non-nutritive, non-food substances is used as a means of weight control, anorexia nervosa is the primary diagnosis.^[10]
• Factitious disorder
  • Some individuals with factitious disorder may intentionally ingest foreign objects as part of falsification of physical symptoms, and there is an element of deception that is consistent with deliberate intent to cause injury or disease.^[11]
• Non-suicidal self-injury and non-suicidal self-injury behaviours in personality disorders
  • Some individuals with personality disorders may swallow potentially harmful items (e.g. - blades, pins, needles, knives) in the context of maladaptive behaviour patterns associated with non-suicidal self-injury.

• Although vitamin or mineral deficiencies (e.g. - zinc, iron) has been reported in some instances, often no specific abnormalities are found.^[12]
• If there is gastrointestinal obstruction, then imaging such as abdominal X-rays, and/or ultrasound to assess for obstructions may be required.^[13]

• Abdominal and gastrointestinal tract examination may be indicated if there is concern about injury to these organ systems.