National Eating Disorders Association

Overview & Essential Statistics

Pica is an eating disorder that involves eating items that are not typically thought of as food and that do not contain significant nutritional value, such as hair, dirt, and paint chips. 

Warning Signs & Symptoms

  • The persistent eating, over a period of at least one month, of substances that are not food and do not provide nutritional value.
  • The ingestion of the substance(s) is not a part of culturally supported or socially normative practice (e.g., some cultures promote eating clay as part of a medicinal practice).
  • Typical substances ingested tend to vary with age and availability. They may include paper, soap, cloth, hair, string, wool, soil, chalk, talcum powder, paint, gum, metal, pebbles, charcoal, ash, clay, starch, or ice. 
  • The eating of these substances must be developmentally inappropriate. In children under two years of age, mouthing objects—or putting small objects in their mouth—is a normal part of development, allowing the child to explore their senses. Mouthing may sometimes result in ingestion. In order to exclude developmentally normal mouthing, children under two years of age should not be diagnosed with pica.
  • Generally, those with pica are not averse to ingesting food. 

Risk Factors

  • Pica often occurs with other mental health disorders associated with impaired functioning (e.g., intellectual disability, autism spectrum disorder, schizophrenia). Between 4%-26% of institutionalized individuals are believed to have pica. 
  • Iron-deficiency anemia and malnutrition are two of the most common causes of pica, followed by pregnancy. In these individuals, pica is a sign that the body is trying to correct a significant nutrient deficiency. Treating this deficiency with medication or vitamins often resolves the problems.
  • A medical professional should assess if the behavior is sufficiently severe to warrant independent clinical attention (e.g., some women may eat nonfood items during pregnancy, but their doctor may determine that their actions do not indicate the need for separate clinical care).

Health Consequences

  • Mechanical bowel problems, such as a physical obstruction of the intestine, caused by ingested items.
  • Intestinal obstruction, or a blockage that prevents food and water from passing through the intestines.
  • Bezoar, a mass of indigestible material found trapped in the gastrointestinal tract (esophagus, stomach, or intestines).
  • Intestinal perforation, caused by the ingestion of a nonfood item that creates a hole in the wall of the stomach, intestines or bowels. 
  • Infections such as toxoplasmosis and toxocariasis may occur as a result of ingesting feces or dirt.
  • Poisoning, such as heavy metal poisoning caused by the ingestion of lead-based paint.

Evaluation & Diagnosis

  • There are no laboratory tests for pica. Instead, the diagnosis is made from a clinical history of the patient.
  • Diagnosing pica should be accompanied by tests for anemia, potential intestinal blockages, and toxic side effects of substances consumed (ie, lead in paint, bacteria or parasites from dirt).

Treatment

The first-line treatment for pica involves testing for mineral or nutrient deficiencies and correcting those. In many cases, problem eating behaviors disappear as deficiencies are corrected. If the behaviors aren’t caused by malnutrition or don’t stop after nutritional treatment, a variety of behavioral interventions are available. 

Scientists in the autism community have developed several different effective interventions, including redirecting the person’s attention away from the desired object and rewarding them for discarding or setting down the non-food item.

Additional Information

  • It is unclear how many people are affected by pica. It most likely is more prevalent in underdeveloped countries.
  • Pica can affect children, adolescents, and adults of both genders.
  • Those who are pregnant and craving nonfood items should only be diagnosed with pica when their cravings lead to ingesting nonfood items, and the ingestion of those items poses a potential medical risk (either due to the quantity or type of item being ingested). 
  • Pica can be associated with intellectual disability, trichotillomania (hair pulling disorder), and excoriation (skin picking) disorder.

References:

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, VA, American Psychiatric Association, 2013.

Bryant‐Waugh, R., Markham, L., Kreipe, R. E., & Walsh, B. T. (2010). Feeding and eating disorders in childhood. International Journal of Eating Disorders, 43(2), 98-111.

Fairburn, C. G., & Walsh, B. T. (2002). Atypical eating disorders (eating disorder not otherwise specified). Eating disorders and obesity: A comprehensive handbook, 2, 171-177.

Pediatric feeding and eating disorders: current state of diagnosis and treatment. Kelly NR, Shank LM, Bakalar JL, Tanofsky-Kraff M. Curr Psychiatry Rep. 2014 May;16(5):446. 

Pica: an age-old eating disorder that's often missed. Mishori R, McHale C. J Fam Pract.  2014 Jul;63(7):E1-4. Review. 

Pica and rumination behavior among individuals seeking treatment for eating disorders or obesity. Delaney CB, Eddy KT, Hartmann AS, Becker AE, Murray HB, Thomas JJ. Int J Eat Disord. 2015 Mar;48(2):238-48.

Risk of human exposure to arsenic and other toxic elements from geophagy: trace element analysis of baked clay using inductively coupled plasma mass spectrometry. Al-Rmalli SW, Jenkins RO, Watts MJ, Haris PI. Environ Health. 2010 Dec 23;9:79. 

Rose, E. A., Porcerelli, J. H., & Neale, A. V. (2000). Pica: common but commonly missed. The Journal of the American Board of Family Practice, 13(5), 353-358.

Trichobezoar: a diagnosis which is hard to swallow and harder to digest. Sanneerappa PB, Hayes HM, Daly E, na Moodley V. BMJ Case Rep. 2014 Apr 30;2014. 

Urszula Kelley, MD