How should I evaluate and manage a patient who presents with persistent ingestion of non‑food substances (pica), including history, laboratory workup, treatment of nutritional deficiencies, behavioral interventions, and possible pharmacotherapy?

Evaluation and Management of Pica

Screen all patients with suspected pica for iron deficiency anemia and nutritional deficiencies first, as iron-deficiency pica typically resolves completely with iron replacement therapy alone, making this the most critical initial step. 1

Initial Clinical Assessment

History Taking

• Document the specific non-food substances ingested (earth, ice, starch, foam, paper, etc.), frequency of ingestion, duration (must be ≥1 month), and quantity consumed. 2, 3
• Assess for developmental history, including age of onset, as pica is common in childhood but persistence beyond early developmental stages suggests underlying pathology. 2
• Screen for psychiatric comorbidities, particularly autism spectrum disorder, intellectual disability, schizophrenia, and obsessive-compulsive features, as 87% of pica patients have associated psychiatric conditions. 4
• Evaluate for compulsive features: increased anxiety when prevented from engaging in pica, soothing effect after ingestion, and ritualistic seeking behaviors suggest an addictive or obsessive-compulsive component. 4
• Document history of early childhood neglect or lack of affect, as precocious affective deprivation is consistently found in pica patients. 4
• Assess for gluttony or indiscriminate oral behaviors (inability to distinguish edible from non-edible substances), present in 87% of cases. 4

Physical Examination

• Measure vital signs including temperature, heart rate, blood pressure, and orthostatic changes to detect complications from malnutrition or toxicity. 5
• Document height, weight, and BMI to assess nutritional status. 5
• Examine for signs of complications: abdominal tenderness or distension (bowel obstruction), dental erosion or injury, signs of lead toxicity (neurologic changes), or respiratory distress (aspiration). 4, 1

Laboratory Workup

Essential Initial Tests

• Obtain complete blood count to detect anemia (particularly microcytic anemia suggesting iron deficiency), leukopenia, or other hematologic abnormalities. 5
• Order comprehensive metabolic panel including electrolytes (sodium, potassium, chloride), liver enzymes, and renal function tests to identify hypokalemia, hyperkalemia, or organ dysfunction from toxin exposure. 5, 1
• Measure serum iron studies (ferritin, serum iron, total iron-binding capacity, transferrin saturation) as iron deficiency is the most treatable cause of pica. 1
• Check zinc level, as zinc deficiency has been associated with pica. 1

Additional Testing Based on Ingested Substances

• Order lead level if geophagia (earth eating) or paint chip ingestion is present, as lead poisoning is a serious complication. 1
• Obtain stool examination for ova and parasites in patients with geophagia or coprophagia to detect intestinal parasitosis. 4
• Consider abdominal X-ray as a standard imaging study for any patient with gastrointestinal symptoms, as anamnesis is often difficult and radiography can reveal ingested foreign bodies. 4
• Measure mercury and phosphorus levels if specific substance exposure warrants. 1

Treatment of Nutritional Deficiencies

Iron Deficiency Management

• Initiate oral iron supplementation immediately (ferrous sulfate 325 mg three times daily or equivalent) if iron deficiency is documented, as pica secondary to iron deficiency typically remits completely after iron therapy. 1
• Reassess pica behavior after 4–6 weeks of iron replacement; resolution of pica with iron repletion confirms iron deficiency as the primary etiology. 4, 1

Other Nutritional Interventions

• Supplement zinc if deficiency is documented. 1
• Correct folate deficiency if present, particularly in patients with restricted diets. 3
• Monitor nutritional status with serial weight measurements and repeat laboratory testing every 4–6 weeks until deficiencies resolve. 3

Behavioral Interventions

First-Line Behavioral Treatment

• Implement a multicomponent behavioral treatment program that targets the motivating operations evoking pica, disrupts its occurrence, and reinforces adaptive alternatives, as this approach reduces pica by at least 90% in 91% of cases. 6
• Apply differential reinforcement strategies: provide positive reinforcement for appropriate eating behaviors and withholding of non-food items. 6
• Use response blocking to physically prevent access to non-nutritive substances when pica behavior is anticipated. 6
• Modify the environment to remove or restrict access to preferred pica substances. 6

Cognitive-Behavioral Approaches

• Consider cognitive-behavioral therapy for patients with compulsive features, as pica may represent an acquired behavior amenable to CBT techniques. 4
• Implement institutional management including supportive care, restoration of self-confidence, and compassionate approaches, particularly in residential or inpatient settings. 4

Pharmacotherapy

Serotonin Reuptake Inhibitors

• Prescribe a selective serotonin reuptake inhibitor (SSRI) such as fluoxetine or sertraline for patients with prominent obsessive-compulsive features or when pica appears related to compulsive activity, as the compulsive nature suggests potential benefit from serotonergic agents. 4

Neuroleptic Therapy

• Use neuroleptic medication (e.g., risperidone, olanzapine) for transient symptom control in patients with psychotic features or severe agitation, though results are often temporary and should not be the sole intervention. 4

Important Contraindications

• Avoid appetite suppressants, weight-loss agents, and stimulants in all pica patients, as these are contraindicated in eating disorders. 7

Multidisciplinary Coordination

Psychiatric Referral

• Refer all pica patients to psychiatry for comprehensive psychiatric evaluation and coordination of multidisciplinary care, as pica requires integrated management. 7
• Screen systematically for depression, anxiety, obsessive-compulsive disorder, and suicidality at every visit. 7

Additional Specialist Involvement

• Consult gastroenterology for patients with abdominal symptoms or suspected bowel obstruction, as surgical complications are common and sometimes life-threatening. 4
• Involve nutrition services to develop meal plans that address nutritional deficiencies and provide adequate oral stimulation. 3
• Engage child and adolescent psychiatry for pediatric cases to address developmental and family dynamics. 3

Monitoring and Follow-Up

Serial Assessment

• Reassess pica frequency and severity at every visit using standardized scales to track treatment response. 4
• Monitor for complications including abdominal pain, constipation, respiratory symptoms, or neurologic changes that may indicate toxicity or obstruction. 4, 1
• Obtain repeat imaging (abdominal X-ray) if new gastrointestinal symptoms develop, given the high incidence of surgical complications. 4

Treatment Adjustment

• Intensify behavioral interventions if pica persists despite nutritional repletion, as non-iron-deficiency pica requires more aggressive behavioral management. 6
• Extend successful treatments to novel implementers, settings, and situations to ensure generalization of behavior change. 6

Critical Pitfalls to Avoid

• Do not dismiss pica as a benign habit; complications include bowel obstruction requiring surgery, lead poisoning, mercury toxicity, hyperkalemia, and death. 4, 1
• Do not delay abdominal imaging in patients with gastrointestinal symptoms, as early detection of foreign bodies prevents life-threatening complications. 4
• Do not rely solely on patient self-report; involve family members or caregivers in history-taking, as patients may conceal pica behavior due to shame or lack of insight. 3
• Do not assume iron deficiency is present without laboratory confirmation; only two of 23 hospitalized pica patients in one study had iron deficiency, and correction did not improve pica in those cases. 4
• Do not use medication monotherapy; pharmacotherapy should always be combined with behavioral interventions and nutritional management. 4