Pica

Overview

Definition

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):
  • Common
  • 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

Epidemiology

• Incidence is challenging to estimate:
  • Diverse clinical definitions
  • Underreported 
• The highest prevalence seen in:
  • Children
  • Pregnant women
• Boys and girls equally affected
• Risk  factors: nutritional deficiency
  • Iron deficiency
  • Zinc deficiency
  • Pregnancy
  • Stress
  • Low socioeconomic status
  • Intellectual disability
  • Child neglect
  • Underlying mental health disorder:
    • Schizophrenia
    • OCD
    • Trichotillomania

Clinical Presentation and Diagnosis

Clinical presentation

• 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

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

Management

Prevention

• Identifying at-risk individuals
• Removing patient from area of exposure 
• Providing food substances with similar texture and color to replace ingested nonfood material

Medical management

• Assess and treat underlying nutritional deficiencies:
  • Iron deficiency anemia
  • Zinc
  • Potassium
• Psychotherapy:
  • CBT (1st-line therapy) 
  • Nutritional rehabilitation
  • Mild aversion therapy
• Treat complications:
  • Medical/surgical bowel clean-out
  • Antiparasitic therapy
  • Treat potential toxicity.

Differential Diagnosis

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).