ICD-116B84	PICA Pica
ICD-10F98.3	Pica of infancy and childhood
DSM-5-TRF98.3 / F50.89	Pica

1. Definition and nosology

Pica (ICD-11: 6B84; DSM-5-TR: F98.3) — persistent (≥ 1 month) ingestion of non-food, non-nutritive substances (clay, hair, paper, soap, metal, stones) — inappropriate for developmental age.

2. History

• “Pica” — from the Latin word for “magpie” (magpie eats everything).
• DSM-III (1980) — As a childhood disorder.
• DSM-5 (2013) — diagnosis possible at all ages.

3. Epidemiology

• Prevalence: children 4–26%, higher in intellectual disability, pregnant women 8–65%, iron deficiency anemia.
• Comorbidity: autism, intellectual disability, iron deficiency, adult malabsorption.

4. Aetiology and pathogenesis

• Nutritional deficiencies (iron, zinc) — may also be reduced due to pica substance ingestion in some patients.
• Neurodevelopmental disorders (autism, ID).
• Pregnancy — physiological and micronutrient.
• Cultural — consumption of clay in some traditions (geophagy).

5. Clinical features

• Geophagy (clay, soil), trichophagy (hair), pagophagy (ice), amylophagy (starch), plumbophagy (paint — lead risk).
• Complications: intestinal obstruction (trichobezoar), lead poisoning, parasitic infection, dental injury, perforation.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Persistent intake of substances with no nutritional value ≥ 1 month.

B. The behavior is not developmentally appropriate (≥ 2 years of age).

C. Not a culturally or socially accepted practice.

D. If occurring in the context of another mental disorder or medical condition — additional diagnosis required (especially in ID and ASD).

6.2 Source-specific clarifications

• DSM-5-TR requires a duration of at least 1 month; ICD-11 sets no duration criterion — it says “persistent or severe enough to require clinical attention”. The developmental age of about 2 years is the same in both.

6.3 Diagnostic algorithm

1. Interview + observation.
2. Laboratory — complete blood count, ferritin, iron, lead level, zinc.
3. Abdominal imaging (obstruction).
4. Neurodevelopmental assessment.

6.4 Differential diagnosis

7. Examination and assessment

• Iron, lead, zinc, parasite tests.
• Abdominal X-ray / USG.

8. Treatment

1. Correction of nutritional deficiency (iron, zinc).
2. Behavioral intervention — habit reversal, environmental modification, alternative stimuli.
3. Intellectual disability comorbid with ASD — functional behavior analysis and ABA-based approach.
4. Medical management of complications (lead poisoning — chelation only with specific indication).
5. During pregnancy — nutritional support.

Source-specific specifications

• AAP — pica assessment and lead screening in children.

Treatment methods

1. Functional Behavior Analysis (FBA) — Identification of behavior trigger and maintainer.
2. Environmental Modification — Restriction of access to non-food substances.
3. Nutritional Correction — Iron, zinc, vitamin supplements.
4. ABA-based intervention — In ID and ASD.

9. Prognosis

• Remission in children through nutritional correction and behavioral intervention.
• May persist on an ID/ASD background; long-term follow-up.

10. Myths and misconceptions

Myth 1: “Pica is just a child's ‘exploratory’ behavior”

Evidence: General developmental part up to 2 years; subsequent continuation is clinical and poses a risk of complications.

Myth 2: “Lead poisoning requires chelation for everyone”

Evidence: chelation only confirmed at high levels (BLL ≥ 45 µg/dL typical); environmental remediation first-line at lower levels.

Myth 3: “Pica in pregnancy is 'the baby's wish', requires no intervention”

Evidence: iron or other deficiency marker; nutritional correction recommended.

Myth 4: “Pica in an ID/ASD patient is ‘inevitable’”

Evidence: Behavioral interventions (ABA, FBA) are effective; the “inevitable” explanation leads to severe complications such as trichobezoar, obstruction.

11. Sources

1. WHO. ICD-11. 6B84 Pica. 2024.
2. APA. DSM-5-TR. 2022.
3. Young S.L. Pica in pregnancy: new ideas about an old condition. Annu Rev Nutr 2010;30:403–422.
4. Hyman S.L. et al. AAP 2020 Clinical Report (ASD). Pediatrics 2020;145(1):e20193447.