What is the appropriate workup for a patient presenting with pica?

Diagnostic Workup for Pica in a 40-Year-Old Female

The appropriate workup for a 40-year-old female with pica (baby powder consumption) should begin with iron studies, complete blood count, and comprehensive metabolic panel to identify underlying nutritional deficiencies, particularly iron deficiency anemia.

Initial Assessment

History Taking

• Gather a thorough exposure history focused on:
  • Duration and frequency of baby powder consumption
  • Quantity consumed
  • Temporal relationship between consumption and symptoms
  • Other non-food items consumed currently or previously
  • Previous episodes of pica behavior
  • Pregnancy status (as pica is common in pregnancy)
  • Cultural beliefs or practices related to consumption
  • Psychiatric symptoms or history
  • Family history of similar behaviors

Laboratory Evaluation

1. First-line testing:

   • Complete blood count (CBC) with peripheral smear
   • Iron studies (serum iron, ferritin, total iron binding capacity)
   • Comprehensive metabolic panel
   • Lead level (venous blood sample)
   • Zinc level

2. Additional testing based on clinical suspicion:

   • Vitamin B12 and folate levels
   • Thyroid function tests
   • Hemoglobin electrophoresis (if anemia is present)
   • Pregnancy test (if applicable)

Radiologic Evaluation

• Abdominal X-ray to evaluate for:
  • Intestinal obstruction
  • Presence of radiopaque foreign materials
  • Complications from ingested substances

Specialized Assessment

Psychiatric Evaluation

• Screen for:
  • Obsessive-compulsive disorder
  • Autism spectrum disorder
  • Intellectual disability
  • Schizophrenia or other psychotic disorders
  • Stress-related disorders

Environmental Assessment

• Evaluate for:
  • Lead exposure in home environment
  • Access to potentially harmful substances
  • Home safety evaluation if severe pica is present

Management Algorithm

1. If iron deficiency is identified:

   • Initiate iron supplementation
   • Monitor response to treatment
   • Re-evaluate pica behavior after correction of deficiency

2. If lead toxicity is identified:

   • Blood lead levels should be interpreted as follows 1:
     • <5 μg/dL: Monitor and identify sources
     • 5-14 μg/dL: Environmental investigation needed
     • 15-44 μg/dL: Confirmation within 1-4 weeks

     • 44 μg/dL: Urgent confirmation within 48 hours, consider chelation

3. If psychiatric condition is identified:

   • Refer for appropriate psychiatric management
   • Consider behavioral therapy approaches, particularly for compulsive features 2

4. If no underlying medical cause is identified:

   • Consider behavioral therapy
   • Evaluate for environmental triggers
   • Monitor for complications

Important Considerations

• Pica is strongly associated with iron deficiency anemia, which may involve disrupted dopamine transmission 3
• The diagnostic criteria for pica per DSM-5 require ingestion of non-nutritive substances for at least one month at a developmentally inappropriate age 3
• Pica can lead to serious complications including intestinal obstruction, parasitic infections, and toxic effects from consumed substances 2
• Baby powder (talc) consumption specifically may lead to respiratory complications if aspirated and potential toxicity depending on composition

Common Pitfalls to Avoid

• Failing to screen for iron deficiency, which is the most common treatable cause of pica
• Overlooking psychiatric comorbidities that may contribute to or exacerbate pica
• Assuming pica will resolve spontaneously without addressing underlying causes
• Focusing only on the pica behavior without evaluating for potential complications
• Neglecting to assess for lead toxicity, which can both cause and result from pica behavior

Remember that pica can be treated effectively when the underlying cause is identified and addressed properly, with nutritional deficiencies being a primary consideration in adult patients.