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 Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation, hypokalemia Hypokalemia Hypokalemia is defined as plasma potassium (K+) concentration < 3.5 mEq/L. Homeostatic mechanisms maintain plasma concentration between 3.5-5.2 mEq/L despite marked variation in dietary intake. Hypokalemia can be due to renal losses, GI losses, transcellular shifts, or poor dietary intake. 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 Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. 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 Schizophrenia Schizophrenia is a chronic mental health disorder characterized by the presence of psychotic symptoms such as delusions or hallucinations. The signs and symptoms of schizophrenia are traditionally separated into 2 groups: positive (delusions, hallucinations, and disorganized speech or behavior) and negative (flat affect, avolition, anhedonia, poor attention, and alogia). Schizophrenia
    • OCD OCD Obsessive-compulsive disorder (OCD) is a condition characterized by obsessions (recurring and intrusive thoughts, urges, or images) and/or compulsions (repetitive actions the person is compelled to perform) that are time-consuming and associated with functional impairment. Obsessive-compulsive Disorder (OCD)
    • Trichotillomania Trichotillomania Trichotillomania (hair-pulling disorder (HPD)) is defined as repetitive pulling of one's hair resulting in hair loss that may be visible to others. This disorder is classified under obsessive-compulsive and related disorders, as there is tension prior to the act that is relieved after the hair-pulling. 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 Autism spectrum disorder Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a "spectrum" because of the wide variability in the severity of symptoms exhibited. 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 Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview
• Lead testing if patient ingests paint
• Basic metabolic panel to identify hypokalemia Hypokalemia Hypokalemia is defined as plasma potassium (K+) concentration < 3.5 mEq/L. Homeostatic mechanisms maintain plasma concentration between 3.5-5.2 mEq/L despite marked variation in dietary intake. Hypokalemia can be due to renal losses, GI losses, transcellular shifts, or poor dietary intake. Hypokalemia in clay ingestion 
• Testing for parasitic infections that may occur with ingesting soil 
• Abdominal X-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. 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 Iron Deficiency Anemia Iron deficiency anemia is the most common type of anemia worldwide. This form of anemia is caused by insufficient iron due to a decreased supply, an increased loss, or an increased demand. Iron deficiency anemia is seen across all ages, sexes, and socioeconomic strata; however, children, women of childbearing age, and patients from lower socioeconomic strata are at higher risk. Iron Deficiency Anemia
  • Zinc
  • Potassium
• Psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. 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 Anorexia Nervosa Anorexia nervosa is an eating disorder marked by self-imposed starvation and inappropriate dietary habits due to a morbid fear of weight gain and disturbed perception of body shape and weight. Patients have strikingly low BMI and diverse physiological and psychological complications. 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 Antidepressant Antidepressants encompass several drug classes and are used to treat individuals with depression, anxiety, and psychiatric conditions, as well as those with chronic pain and symptoms of menopause. Antidepressants include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and many other drugs in a class of their own. Serotonin Reuptake Inhibitors and Similar Antidepressant Medications medication as an adjunct. Extreme cases may require hospitalization.
• Bulimia nervosa Bulimia nervosa Bulimia nervosa is an eating disorder marked by recurrent episodes of binge eating accompanied by inappropriate compensatory behaviors (laxatives or diuretics use, self-induced vomiting, fasting, or excessive exercise) to counteract the effects of binge eating and prevent weight gain. 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 Rumination Disorder Rumination disorder is a behavioral disorder marked by repeated regurgitation of food, which may be re-chewed, re-swallowed, or spit out. This condition is not due to a medical disorder (GERD or pyloric stenosis) or other eating disorders (avoidant/restrictive food intake disorder, anorexia nervosa, binge eating disorder, or bulimia nervosa). 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 GERD Gastroesophageal reflux disease (GERD) occurs when the stomach acid frequently flows back into the esophagus. This backwash (acid reflux) can irritate the lining of the esophagus, causing symptoms such as retrosternal burning pain (heartburn). Gastroesophageal Reflux Disease): Treatment involves multiple CBT techniques, including biofeedback psychotherapy as well as medication when appropriate (e.g., proton pump inhibitors).