Pica
Pica is an eating disorder in which a person persistently eats non-food substances that have no nutritional value, such as soil, paper, hair, chalk, or pieces of paint. This is not just an unusual preference: the behaviour lasts for at least a month and is not expected for the person's developmental level.
Early evaluation is important because some substances can cause poisoning, intestinal obstruction or perforation, infection, and dental damage. The assessment also looks for possible nutritional deficiencies or co-occurring developmental and mental conditions without considering these to automatically rule out the diagnosis.
What Is Pica?
In pica consumption of non-nutritive, non-food substances is recurrent and persistent enough to require clinical attention. Materials vary by age, environment and availability. A young child putting objects in the mouth is a common developmental stage, so the diagnosis is usually not made before the age of 2 years. Also, a practice that is culturally acceptable is not classified as pica without a careful understanding of the context. Appetite for usual food may be normal, decreased, or variable; normal appetite is not a diagnostic requirement.
Key Features and Signs
The presentation depends on substance, frequency and age, but may include:
- Repeated eating of soil, clay, paper, soap, cloth, hair, ice, chalk, ash or other non-food items.
- Seeking, hiding, or hoarding the material being consumed and difficulty restricting the behaviour.
- Abdominal pain, constipation, vomiting or changes in bowel movements, which may indicate a gastrointestinal complication.
- Fatigue, pallor, or other signs of possible iron deficiency or other nutritional deficiency.
- Dental damage, mouth injuries, infections or symptoms of exposure to toxic substances, depending on the material.
- Co-occurrence with pregnancy, intellectual disability, autism, schizophrenia or other condition, not necessarily present in every case.
How It Is Diagnosed
Diagnosis is based on a detailed history and medical evaluation. The professional needs to know what is consumed, how often, for how long, in what context and with what consequences.
- Eating non-nutritive, non-food substances persists for at least 1 month.
- The behaviour is not developmentally expected and is not a culturally supported or socially acceptable practice.
- When there is another mental or medical condition—such as an intellectual disability, autism, or pregnancy—pica is diagnosed separately only if it is severe enough to require specific clinical management.
- Testing may include blood testing for anaemia, iron or lead, testing for infections, and imaging when there is evidence of a blockage or foreign body.
How It Can Affect Daily Life
The behaviour may create shame, conflict, or a need for increased supervision, particularly when the individual has difficulty assessing risk. At school, work, or home, environmental changes may be needed to reduce access to hazardous materials without punishment or stigmatization. Recurrent medical complications affect eating, concentration, and participation in daily life. Support is most effective when the person and carers understand potential triggers and have a clear safety plan.
Causes and Risk Factors
There is no single cause. Pica has been associated with intellectual disability, autism, certain mental disorders, pregnancy, food insecurity, and deficiencies such as iron deficiency or zinc deficiency. These relationships do not mean that one factor always causes the behaviour. Environmental factors, limited supervision and sensory needs may also play a role in some individuals. The assessment avoids blaming the individual or family and looks at what is maintaining the behaviour in the particular case.
Similar or Co-occurring Conditions
The mode and purpose of ingestion help distinguish pica from other behaviours:
- Developmentally normal oral exploration in children under 2 years of age is not pica.
- In anorexia nervosa, non-food items may be consumed as a means of appetite control; then the eating disorder is evaluated first.
- In factitious disorder, a person may deliberately induce illness or injury, including by ingesting objects, while deceptively presenting themselves as ill.
- Ingestion with the intention of self-harm requires a different risk assessment and should not be automatically considered pica.
- Autism, intellectual disability, schizophrenia, trichotillomania, and Excoriation (Skin-Picking) Disorder may co-occur and require separate management.
Treatment and Support
The plan is tailored to the substance consumed, the complications, the individual's needs, and the function the behaviour may serve.
- Poisoning, blockage, infection, dental damage and nutritional deficiencies are first treated by the appropriate medical specialties.
- A functional behavioural assessment can identify the situations and factors that maintain non-food ingestion and guide safer alternatives and reinforcement of appropriate behaviours.
- Practical changes reduce access to dangerous substances, increase supervision where needed and offer safe sensory substitutes.
- Nutritional assessment and treatment of confirmed deficiencies is done by a professional; supplements should not be taken empirically in high doses.
- The cooperation of family, school, doctor, dietitian and mental health specialist is especially important when there are developmental needs.
When to Seek Help
Seek evaluation when nonfood eating is repeated, lasts for weeks, involves hazardous substances, or is accompanied by pain, fatigue, weight loss, or changes in bowel movements. For a child, do not wait for complications before seeking assessment when the behaviour is beyond the expected developmental stage. Record what may have been consumed, the amount and time, but do not induce vomiting without the direction of a professional or poison centre.
Frequently Asked Questions
Does iron deficiency exclude a diagnosis of pica?
No. Iron deficiency may co-occur and needs treatment, but does not rule out the diagnosis when the rest of the evidence is met. Testing helps identify both deficiency and potential complications.
Is it pica when a young child puts objects in their mouth?
Not necessarily. Oral exploration is expected at very young ages. Pica is considered when there is persistent swallowing, behaviour is developmentally inappropriate and requires clinical attention.
Is pica only treated with supplements?
No. Supplements only have a place when a relevant nutritional deficiency has been confirmed. Complication screening, safety adjustments, and individualised behavioural support are usually needed at the same time.