Initial Approach to Pica Workup
The initial workup for pica should focus on identifying iron deficiency anemia, which is the most strongly associated medical condition with pica behavior.
Definition and Overview
Pica is defined as the persistent ingestion of non-nutritive substances for more than 1 month at an age when this behavior is developmentally inappropriate 1. It occurs most commonly in:
- Children
- Patients with developmental disabilities
- Pregnant women
Diagnostic Criteria (DSM-5)
- Persistent eating of non-nutritive substances for at least 1 month
- The eating behavior is inappropriate for developmental level
- Not part of a culturally supported practice
- If occurring in the context of another mental disorder, severe enough to warrant clinical attention
Initial Workup Algorithm
1. Laboratory Testing
- Complete blood count (CBC) with differential
- Focus on hemoglobin, hematocrit, and red cell indices to identify anemia
- Iron studies
- Serum iron
- Total iron binding capacity (TIBC)
- Ferritin
- Transferrin saturation
Iron deficiency anemia has the strongest association with pica behavior 2. Testing for iron deficiency should be the first step in any pica workup.
2. Additional Laboratory Testing
- Zinc levels
- Lead levels (especially in children with geophagia)
- Comprehensive metabolic panel
- Pregnancy test (for women of childbearing age)
3. Targeted History
- Specific substances consumed
- Duration of behavior
- Frequency of consumption
- Complications experienced
- Developmental history
- Psychiatric history
- Family history of similar behaviors
4. Physical Examination
- Signs of anemia (pallor, tachycardia)
- Abdominal examination for masses or tenderness
- Oral/dental examination for damage
- Neurological examination
- Developmental assessment
5. Imaging (Based on Ingested Materials)
- Abdominal X-ray if ingestion of:
- Metal objects
- Stones
- Other radiopaque materials
- Consider abdominal CT scan for suspected intestinal obstruction
Special Considerations
For Patients with Developmental Disabilities
Patients with developmental disabilities, particularly autism spectrum disorders, may have persistent pica that requires behavioral interventions 3. Applied behavior analysis (ABA) has the most robust empirical support for treating pica in this population.
For Children
Pica often self-remits in younger children but requires monitoring for complications 1. The workup should still include iron studies as the primary investigation.
For Pregnant Women
Pica during pregnancy may indicate nutritional deficiencies that require correction to prevent maternal and fetal complications.
Common Pitfalls to Avoid
- Failing to screen for iron deficiency - This is the most common treatable medical cause of pica
- Overlooking serious complications - Intestinal obstruction, perforation, or toxicity from ingested substances can be life-threatening
- Assuming cultural practices are pathological - Some non-nutritive consumption is normative in certain cultures 2
- Focusing only on psychiatric causes - Medical causes should be ruled out before attributing pica solely to psychiatric conditions
- Neglecting multidisciplinary care - Complex cases benefit from collaboration between medical, psychiatric, and behavioral specialists
By following this systematic approach to the pica workup, clinicians can identify underlying causes and implement appropriate interventions to reduce morbidity and mortality associated with this condition.