Patients with pica tend to eat nontoxic materials (eg, paper, clay, dirt, hair, chalk, string, wool). For children < 2 years, this behavior is considered developmentally appropriate because children of this age frequently mouth and ingest a variety of objects.
Pica is common during pregnancy and in patients with iron-deficiency anemia; the reasons for this have not been determined (1–3).
Usually, pica does not cause significant medical harm. However, some patients develop complications such as
Iron and zinc deficiency (through ingestion of substances such as clay that bind iron and zinc, preventing their absorption)
Intestinal obstruction (caused by impacted ingested materials)
Lead poisoning (eg, from eating paint chips)
A parasitic infestation (eg, from eating dirt)
Swallowing objects in an attempt to cause self-harm or to falsify illness (as occurs in factitious disorder imposed on self) is not considered pica.
Pica itself rarely impairs social functioning, but it often occurs in people with other cognitive disorders or mental illnesses that do impair functioning (eg, autism, intellectual disability, sometimes schizophrenia) (2, 4).
Pica may last several months, then resolve on its own, particularly in children.
References
1. Fawcett EJ, Fawcett JM, Mazmanian D. A meta-analysis of the worldwide prevalence of pica during pregnancy and the postpartum period. Int J Gynaecol Obstet. 2016;133(3):277-283. doi:10.1016/j.ijgo.2015.10.012
2. Schnitzler E. The Neurology and Psychopathology of Pica. Curr Neurol Neurosci Rep. 2022;22(8):531-536. doi:10.1007/s11910-022-01218-2
3. Borgna-Pignatti C, Zanella S. Pica as a manifestation of iron deficiency. Expert Rev Hematol. 2016;9(11):1075-1080. doi:10.1080/17474086.2016.1245136
4. Fields VL, Soke GN, Reynolds A, et al. Pica, Autism, and Other Disabilities. Pediatrics. 2021;147(2):e20200462. doi:10.1542/peds.2020-0462
Diagnosis of Pica
Psychiatric assessment
Sometimes laboratory testing
Pica is diagnosed when the following Diagnostic and Statistical Manual of Mental Disorders, 5th ed, Text Revision (DSM-5-TR) criteria are met (1):
A patient persistently eats nonnutritive, nonfood material for ≥ 1 month.
Ingestion of these materials is inappropriate for the developmental level of the patient.
Ingestion of these materials is not part of a cultural tradition.
If ingestion occurs in a patient with another disorder, it is sufficiently persistent and severe to warrant specific treatment.
Pica is not diagnosed in children < 2 years because at that age, eating such materials is considered part of normal development.
If doctors suspect pica, they evaluate nutritional status to check for weight loss and nutritional deficiencies, including iron deficiency.
Sometimes pica is diagnosed when patients have symptoms of intestinal obstruction (eg, severe cramping, constipation), lead poisoning, or parasitic infestation that trigger a trip to the emergency department or other clinical setting.
Tests may be performed based on the patient's symptoms and/or the substances ingested. They include blood tests to check for lead poisoning when paint chips have been eaten and stool tests to detect parasitic infestation when soil has been eaten.
Diagnosis reference
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed, Text Revision. American Psychiatric Association Publishing; 2022:371-373.
Treatment of Pica
Sometimes behavioral modification
Treatment of nutritional deficiencies and other complications
Behavioral modification techniques may help, but little is known about specific treatments for pica.
Nutritional deficiencies and other complications are treated. Intestinal obstruction may require surgery.
Key Points
Diagnose pica in patients who persistently eat nonnutritive, nonfood material for ≥ 1 month; pica is not diagnosed in children < 2 years.
Usually, pica does not cause significant medical harm, but check patients for weight loss and nutritional deficiencies and, if symptoms suggest it, for intestinal obstruction, lead poisoning, and parasitic infestation.
Behavioral modification techniques may help, but little is known about specific treatments for pica.
Treat nutritional deficiencies and other complications as needed.
