Pica

Understanding Pica

What Pica Is

Pica is the persistent eating of substances that have no nutritional value and are not normally considered food. The behavior must occur for at least one month, must be developmentally inappropriate (eating dirt is normative in a 14-month-old but not in a 6-year-old), and must not be part of a culturally sanctioned practice (such as the ritual consumption of clay in some traditions).

What Pica Is Not

Mouthing of non-food objects by infants and toddlers is normal exploratory behavior, not pica. Cultural practices of consuming clay, ash, or starch for health or ritual reasons are not pica when they are normative and harmless within the cultural context. Brief experimentation does not meet criteria.

The Substance Tells the Story

The substance ingested often points to the underlying mechanism. Ice cravings (pagophagia) are strongly linked to iron deficiency. Clay and earth (geophagia) appear in pregnancy and in cultural contexts. Hair (trichophagia) is associated with trichotillomania and can produce dangerous gastric trichobezoars. Paint chips raise concerns about lead exposure. Asking specifically what is being eaten guides both medical workup and treatment.

DSM-5 Diagnostic Criteria

Criterion A: Persistent Eating

Persistent eating of non-nutritive, non-food substances over a period of at least one month.

Criterion B: Developmentally Inappropriate

The eating of non-nutritive, non-food substances is inappropriate to the developmental level of the individual. The minimum age for diagnosis is typically two years, to exclude normal mouthing behavior in infants and toddlers.

Criterion C: Not Culturally Sanctioned

The eating behavior is not part of a culturally supported or socially normative practice.

Criterion D: Clinical Attention Required

If the eating behavior occurs in the context of another mental disorder (e.g., autism, intellectual disability, schizophrenia) or medical condition (including pregnancy), it is sufficiently severe to warrant additional clinical attention.

Course Specifiers

• In remission: After full criteria for pica were previously met, the criteria have not been met for a sustained period.

Variants of Pica

Pagophagia (Ice)

Compulsive chewing or sucking of ice. The most consistent association is iron-deficiency anemia, and pagophagia frequently resolves with iron repletion. Other associations include dry mouth, oral discomfort, and stimulant use.

Geophagia (Earth, Clay, Soil)

Eating of earth, clay, or chalk. Found in pregnancy, iron deficiency, and certain cultural practices. Geophagia carries risks of parasitic infection, lead and other heavy-metal exposure, and intestinal blockage.

Amylophagia (Starch)

Eating large amounts of laundry starch or raw cornstarch. Common in pregnancy and associated with iron deficiency. May contribute to hyperglycemia and excessive weight gain.

Trichophagia (Hair)

Eating of hair, often associated with trichotillomania (hair-pulling disorder). Can produce a gastric trichobezoar — a mass of accumulated hair — which may require surgical removal and is sometimes accompanied by an intestinal tail (Rapunzel syndrome).

Plumbophagia / Paint Chip Ingestion

Eating paint chips, often from old buildings. The major risk is lead poisoning, particularly in children, with neurodevelopmental consequences.

Coprophagia, Urophagia, and Others

Less common variants involve eating feces, drinking urine, eating burnt matches (cautopyreiophagia), or consuming metal (metallophagia). These often signal severe psychiatric illness and require specialized assessment.

Cellulose and Paper

Eating paper, cardboard, and similar materials is common in children with developmental disability and in some adults under stress. Risk is primarily obstruction.

Pica Across Populations

Children

Pica is most common in young children, but the diagnosis applies only beyond the age and developmental window where mouthing is typical. Persistent pica in children warrants evaluation for iron deficiency, lead exposure, and developmental concerns.

Pregnancy

Pica in pregnancy is reported in a substantial minority of pregnant people worldwide, with rates highly variable by culture. Cravings often focus on ice, clay, or starch. Pregnancy pica is associated with iron-deficiency anemia and can produce maternal and fetal harm; clinical guidance is to evaluate nutritional status and address ingested substances of concern.

Autism and Intellectual Disability

Pica is significantly more common in people with autism, intellectual disability, and severe developmental delay. The behavior may be sensory-driven, self-stimulatory, or related to limited interoceptive awareness. Specialized behavioral intervention is often needed.

Psychiatric Conditions

Pica occurs in schizophrenia, severe OCD, and other psychotic and obsessive disorders. In schizophrenia, the behavior is sometimes driven by delusional beliefs.

Older Adults

Pica in older adults is less common and frequently signals dementia, severe depression, or psychotic illness. New-onset pica in an older adult warrants comprehensive evaluation.

Causes and Risk Factors

Nutritional Deficiency

Iron deficiency is the most robust biological correlate, particularly for pagophagia and geophagia. Zinc deficiency, calcium deficiency, and broader micronutrient gaps have also been implicated. Replenishment of iron stores frequently resolves pica when nutritional deficiency is the driver.

Neurodevelopmental and Sensory

In autism and intellectual disability, pica is often a self-stimulatory or sensory behavior. The texture, taste, or temperature of the substance may be reinforcing. Limited verbal communication can make it hard to identify what is driving the behavior.

Pregnancy

Physiological changes in pregnancy — including iron demand, altered taste sensitivity, and hormonal changes — contribute. Cultural and family transmission of pregnancy pica practices is also documented.

Stress and Trauma

Pica can emerge or worsen in response to stress, trauma, or institutional environments. Pica has been documented in incarcerated populations and in conditions of severe food insecurity.

Obsessive-Compulsive Features

For some people, pica functions like a compulsion — the urge to eat the substance is intrusive, distressing, and resisted with difficulty. This overlap with OCD shapes treatment.

Cultural Practices

Eating of clay or earth has cultural roots in many parts of the world, often connected to fertility, pregnancy, or perceived medicinal benefit. When the practice is normative and harmless in its cultural context, it is not pica.

Medical Complications

Toxicity

• Lead poisoning from paint chips, with neurodevelopmental impairment in children
• Heavy-metal exposure from soil, ceramics, or metallic objects
• Pesticide and chemical exposure from contaminated material
• Mercury exposure from certain substances

Gastrointestinal

• Intestinal obstruction (bezoars, masses of indigestible material)
• Perforation from sharp objects
• Esophageal or gastric mucosal injury
• Constipation
• Rapunzel syndrome (trichobezoar extending into the small intestine)

Infectious

• Parasitic infections from soil consumption (toxocariasis, ascariasis)
• Bacterial infections from contaminated material

Dental

• Tooth fracture from hard substances
• Dental erosion
• Temporomandibular joint dysfunction

Nutritional

Pica can both result from and contribute to nutritional deficiency. Eating non-nutritive substances may displace actual food, may bind iron or zinc and impair absorption, or may signal an underlying deficiency that requires repletion.

Assessment and Diagnosis

Direct Inquiry

Most patients and families will not spontaneously disclose pica. Direct, non-judgmental questions are essential — for example, "Do you ever eat or chew on things that aren't normally considered food?" Common substances should be named: ice, clay, paper, hair, paint chips, soap.

Standardized Tools

• Pica, ARFID, and Rumination Disorder Interview (PARDI): Structured interview covering pica
• Children's Eating Behaviour Inventory: Pediatric measure including pica items

Medical Workup

• Complete blood count and iron studies
• Lead level — particularly in children and in suspected paint or soil ingestion
• Zinc, calcium, ferritin
• Stool studies for parasites when geophagia is involved
• Abdominal imaging when obstruction or bezoar is suspected

Differential Diagnosis

• Normal mouthing in children under age 2
• Culturally sanctioned consumption practices
• Anorexia or bulimia with unusual eating behavior tied to weight control
• Factitious disorder with self-induced harm
• Trichotillomania with hair ingestion (both diagnoses may apply)

Treatment Approaches

Treat the Underlying Cause

When iron deficiency is identified, repletion alone often resolves pica — particularly pagophagia. Treating dental issues, oral pain, and other contributing medical conditions is essential.

Behavioral Intervention

For children and individuals with developmental disability, behavior analytic approaches are the strongest evidence base. Techniques include:

• Functional behavior assessment to identify the function of pica
• Differential reinforcement of alternative behaviors
• Environmental modification (removing accessible non-food items)
• Response interruption and redirection
• Sensory substitution (offering safe alternatives that meet the sensory need)

Cognitive Behavioral Therapy

For adults and adolescents with pica that functions as a compulsion or stress response, CBT — sometimes with exposure and response prevention principles — can reduce urges and behaviors. Concurrent treatment of OCD or trichotillomania, when present, is essential.

Pharmacotherapy

No medication is FDA-approved for pica. SSRIs have limited evidence and are used when OCD or anxiety is prominent. In severe pica with self-injurious features, atypical antipsychotics have been used. Pharmacotherapy is generally adjunctive, not stand-alone.

Surgical Intervention

Bezoars, perforations, and obstructions may require endoscopic or surgical removal. Pediatric and gastroenterology consultation is essential when ingestion of sharp objects, magnets, or large quantities of indigestible material is suspected.

Environmental Safety

For pica involving toxic or dangerous substances, environmental safety planning is part of treatment. Lead remediation, removal of accessible chemicals, and structured supervision in residential or school settings reduce risk.

Supporting a Loved One

For Parents

• Childproof the environment — remove access to substances that are toxic or pose obstruction risk
• Avoid punishment for pica; it rarely works and increases secrecy
• Bring the behavior to a pediatrician; insist on iron testing
• Work with behavioral specialists if pica persists or co-occurs with autism or developmental disability

For Partners and Family of Adults

• Approach with compassion — pica is often hidden because of shame
• Encourage medical evaluation for nutritional deficiency
• Avoid shaming, which intensifies secrecy
• Recognize pica that emerges in pregnancy as a medical concern, not a quirk

What to Avoid

• Treating the behavior as moral failure or bizarre choice
• Force, shaming, or restrictive punishments
• Assuming the behavior will "go away on its own" when medical risk is present