Summary
Pica is an eating disorder characterized by the persistent ingestion of nonnutritive nonfood substances. Causes are multifactorial and include nutritional deficiencies, pregnancy, and developmental disorders. Diagnostic workup depends on the substance consumed but usually involves evaluation for anemia as an underlying cause and screening for associated complications (e.g., lead toxicity, GI complications, parasitic infections). Management involves addressing any underlying causes and/or nutritional deficiencies followed by behavioral interventions (e.g., positive reinforcement). Selective serotonin reuptake inhibitors (SSRIs) may be considered in patients with pica refractory to initial management.
Epidemiology
- Prevalence: highest in children ≤ 6 years of age, during pregnancy, and in individuals with certain psychiatric comorbidities (see “Etiology of pica”) [1]
- Sex
Epidemiological data refers to the US, unless otherwise specified.
Etiology
The etiology is not entirely understood. Pica is associated with: [1][3]
- Nutritional deficiencies (iron deficiency, zinc deficiency)
- Pregnancy [4]
- Low socioeconomic status
- Psychosocial trauma (e.g., due to maternal deprivation, child neglect):
- Intellectual developmental disorder
- Autism spectrum disorder
- Dementia
- Schizophrenia
- Attention-deficit hyperactivity disorder
Clinical features
- Examination is usually normal. [3]
- Complications of pica (e.g., dental damage, GI symptoms) may be present depending on the substance consumed. [3]
Diagnostics
Approach [3]
- Assess patients using the DSM-5 diagnostic criteria for pica.
- For patients who meet the criteria:
- Evaluate for anemia.
- Request a pregnancy test for patients of childbearing age.
- Workup for complications of pica (e.g., bezoar, bowel obstruction).
- Consider screening for parasites and/or heavy metals depending on the ingested substance.
- For children with pica, consider assessment for neurodevelopmental disorders.
Diagnostic criteria
| DSM-5 diagnostic criteria for pica [3][5] | |
|---|---|
| Definition |
|
| Duration |
|
| Additional features |
|
| All criteria must be fulfilled. | |
Laboratory studies [1][3]
-
Diagnostic studies for anemia, e.g.: [1]
- CBC with differential: May also reveal eosinophilia, suggestive of a parasitic infection (see “Complications of pica”)
-
Peripheral smear
- Hypochromic, microcytic anemia may be caused by iron deficiency or lead toxicity
- Basophilic stippling suggests lead toxicity [1]
- Iron studies
- Pregnancy test for patients of childbearing age
- Consider the following based on the ingested substance:
Imaging
- Suspected bezoar or obstruction [1][3]
- CT abdomen and/or abdominal ultrasound
- See also “Diagnostics of bowel obstruction.”
- Suspected lead ingestion
- X-ray abdomen to assess for paint chips and/or retained foreign bodies in the GI tract [6]
- X-ray long bones to assess for lead lines [1]
Management
Approach [1][3]
- Management involves a multidisciplinary team (e.g., physicians, dietitians, social workers, dentists).
- Screen for red flags for eating disorders and, if present, admit for inpatient management.
-
Address any underlying causes, e.g.:
- Micronutrient or electrolyte abnormalities: See “Iron therapy for iron deficiency anemia” and “Electrolyte repletion.”
- Mental health disorders: See “Treatment of ADHD” and “Treatment of schizophrenia.”
- Treat associated complications of pica (e.g., treatment of malnutrition, lead poisoning, bowel obstruction).
- Educate patients and caregivers on the condition and potential complications.
- Start behavioral interventions.
- For patients with refractory symptoms, SSRIs may be considered.
Behavioral interventions [1][3]
- Suggest substitutions (e.g., replacing sand and pebbles with Grape Nuts). [7]
- Educate caregivers to:
- Help children to distinguish between edible and nonedible substances.
- Use behavioral strategies (e.g. positive reinforcement, time-out).
- Referral for behavioral therapy or psychotherapy may be necessary, especially for patients with intellectual disabilities.
Pica in pregnancy and young children is typically self-limited. [3]
Complications
- Poor nutritional status [1]
-
Heavy metal poisoning [1]
- Lead poisoning, e.g., from paint ingestion (most common)
- Mercury poisoning
- Arsenic poisoning
-
GI complications [3]
- Constipation
- Ulceration from consumption of corrosive substances
- Bowel obstruction from the consumption of indigestible objects (which may form a bezoar)
- Bowel perforation from the ingestion of sharp objects
- Bacterial or parasitic infections from the ingestion of contaminated dirt or food, e.g.: [1]
- Dental complications: from mechanical damage to teeth [3]
- Electrolyte and/or acid-base abnormalities: for example, metabolic alkalosis from the ingestion of baking soda [1]
We list the most important complications. The selection is not exhaustive.
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