Pica is an eating disorder of unclear etiology characterized by a desire or compulsion to eat substances that are not food in a context that is not developmentally, socially, or culturally appropriate.
The specific substances that are craved vary:
- Geophagia (earth ingestion):
- Leads to constipation, hypokalemia with myopathy, and nutritional deficiencies
- Can be a source of parasites
- Lead poisoning can be a serious complication with clay ingestion.
- Pagophagia (ice ingestion):
- Associated with iron deficiency
- Tooth decay and sensitivity
- Amylophagia (excessive starch ingestion):
- Iron deficiency
- High blood sugar and obesity
- Incidence is challenging to estimate:
- Diverse clinical definitions
- The highest prevalence seen in:
- Pregnant women
- Boys and girls equally affected
- Risk factors: nutritional deficiency
- Iron deficiency
- Zinc deficiency
- Low socioeconomic status
- Intellectual disability
- Child neglect
- Underlying mental health disorder:
Clinical Presentation and Diagnosis
- Patients self-present or are brought in by caregivers when abnormal eating habit is noticed.
- May also present with complications:
- Toxicity and poisoning (e.g., lead poisoning if ingesting paints or clay)
- Hypokalemia (clay ingestion)
- GI obstruction (bezoar ingestion)
- Parasitic infection (sand, mud, clay ingestion)
- Patients do not have self-harm/suicidal intention; distinguish from intentional intoxication/overdose.
Diagnosis of pica is clinical, based on observed patterns of behavior:
- Recurrent episodes of eating nonfood, nonnutritional substances (e.g., chalk, clay, cloth, coal, dirt, gum, hair, metal, paint, paper, pebbles, soap, string, or wool)
- Eating behavior is inappropriate to the patient’s developmental level and is not culturally supported or socially normal.
- Lasts at least 1 month
- Exclude autism spectrum disorder, developmental delay, and intellectual disability.
Further testing should be directed by etiology, symptomatology, and ingested substances:
- Blood cell counts and iron studies to diagnose anemia
- Lead testing if patient ingests paint
- Basic metabolic panel to identify hypokalemia in clay ingestion
- Testing for parasitic infections that may occur with ingesting soil
- Abdominal X-rays to identify intestinal obstruction by bezoars
- Identifying at-risk individuals
- Removing patient from area of exposure
- Providing food substances with similar texture and color to replace ingested nonfood material
- Assess and treat underlying nutritional deficiencies:
- Iron deficiency anemia
- CBT (1st-line therapy)
- Nutritional rehabilitation
- Mild aversion therapy
- Treat complications:
- Medical/surgical bowel clean-out
- Antiparasitic therapy
- Treat potential toxicity.
Pica is classified as an eating disorder and can have features in common with other such disorders.
- Anorexia nervosa: eating disorder characterized by intense fear of gaining weight, restrictive dietary habits, and distorted body image: Patients affected by anorexia nervosa are usually underweight and are reluctant to seek medical help. Treatment involves CBT with antidepressant medication as an adjunct. Extreme cases may require hospitalization.
- Bulimia nervosa: anxiety-driven eating disorder defined by recurrent episodic binge eating paired with recurrent inappropriate compensatory behavior (inducing vomiting, laxative abuse, and excessive exercising): The BMI of patients with this condition may be normal or even elevated. Patients with bulimia nervosa are more likely to seek help. Treatment involves a combination of CBT and selective serotonin reuptake inhibitor (SSRI) medication.
- Binge-eating disorder: eating disorder marked by recurrent episodes of binge eating without inappropriate compensatory behavior: Binge-eating disorder results in fluctuating body weight. Episodes occur at least weekly for 3 months. Treatment consists of a combination of psychotherapy and pharmacotherapy.
- Rumination disorder: repeated regurgitation of food (which may be re-chewed, re-swallowed, or spit out) that is not due to a general medical condition (e.g., GERD): Treatment involves multiple CBT techniques, including biofeedback psychotherapy as well as medication when appropriate (e.g., proton pump inhibitors).
- American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5). Arlington, VA: American Psychiatric Association.
- McNaughten B, Bourke T, Thompson A. (2017). Fifteen-minute consultation: the child with pica. Arch Dis Child Educ Pract Ed. https://pubmed.ncbi.nlm.nih.gov/28487433/
- Call NA, Simmons CA, Mevers JE, Alvarez JP. (2015). Clinical outcomes of behavioral treatments for pica in children with developmental disabilities. J Autism Dev Disord. https://pubmed.ncbi.nlm.nih.gov/25636679/