Pica (PIE-ka) is an eating disorder described in the DSM-5 * in which a person repeatedly eats non-food items. It is common for children under age two to taste or eat material such as dirt, chalk, or paint chips, but if the practice continues after about age two, medical and psychological intervention is needed to break the habit.
Allison was babysitting her cousin Rory at the playground in the park. At first Rory played happily, piling sand into a heap in the sandbox. Allison looked down to check for messages on her phone. When she looked up, Rory was stuffing sand into his mouth. Allison rushed over and made Rory spit the sand out, but soon he picked up another handful and tried to eat it. Allison knew that babies often put weird things in their mouths, but Rory was three years old and no longer a baby. She decided she should take Rory out of the sandbox and tell her aunt about his sand eating when they got home.
People with pica have an eating disorder that drives them to intentionally eat non-food material. Infants and young toddlers often lick or eat nonfood items. This is a normal way for babies to learn about the world. When the practice continues regularly for at least one month in a person over two years old, the child is considered to have an eating disorder. In people with developmental delays, intellectual disabilities, and some mental health disorders, pica may continue into the teenage years and adulthood.
Dirt, clay, pebbles, sand, chalk, paper, glue, laundry starch, plaster, paint chips, coffee grounds, soap, hair, cigarette butts, burnt match heads, and feces (FEE-sees) * are some of the non-food materials that people with pica will eat. Doctors don't know why these materials are attractive, but reasons are thought to be:
Pica is most common in children between the ages of two and six years old and occurs with equal frequency in both boys and girls. Researchers find it difficult to determine exactly how many children have pica because the behavior often goes unrecognized and disappears on its own in developmentally normal, healthy children. In addition, some forms of pica, especially eating dirt, clay, or laundry starch, are culturally acceptable and considered normal among some groups, especially in developing countries. For example, dirt to eat is sold in Uganda.
Pica is most common in people who have intellectual disabilities, autism, developmental delays, obsessive-compulsive disorder, and schizophrenia. Various estimates suggest that 4 to 26 percent of this population have the disorder. Although most people with pica are under age six, among people with intellectual disabilities, pica occurs most often in people 10 to 20 years old.
Rarely do adults without developmental disabilities or mental health disorders develop pica. The exception is in developmentally normal pregnant women who often start eating starch. It is thought that this is a culturally learned behavior, and that starch is supposed to control nausea during the early months of pregnancy. Starch eating usually stops when the pregnancy ends.
Pica is not contagious, although it can be a learned behavior, especially among groups where eating dirt, clay, or other non-food items is considered culturally normal.
Researchers do not know why some people develop pica. Risk factors include malnutrition, a biochemical imbalance in the body, high levels of stress, poverty, lack of adult attention, a cultural environment that accepts pica, intellectual disability, developmental delay, and certain mental health disorders.
Non-food material can also cause digestive problems. When it collects in the stomach and intestine it can cause diarrhea or constipation. The intestines may be blocked or punctured if the material is sharp. (Some people have been known to eat light bulbs.) This creates a medical emergency. Dirt and feces can contain bacteria and parasites that cause serious illness and infection. Eating sand and chewing pebbles causes tooth damage. Teeth may break and the enamel may wear off making them more likely to develop cavities.
To be diagnosed with pica a person must repeatedly eat non-food items for a period of one month or more and attempt to eat the non-food material even when restrained. The behavior must be inappropriate for the age and developmental stage of the person, and the non-food item should not be eaten as part of a cultural or religious practice.
No single test will detect pica. When pica is suspected, the doctor will do a complete health and behavioral history. Behaviors associated with eating non-food material usually are described by parents or caregivers and not by the patient, who is often a child or intellectually handicapped.
Blood tests may be done to detect anemia, low levels of iron and zinc, and high levels of lead. Other tests may be done to determine if the patient has vitamin deficiencies, especially if the patient appears malnourished. The stomach and intestines may be examined using x rays and endoscopy * . Other tests may be done to detect parasites or infections acquired through eating dirt or feces.
Although pica can disappear on its own, when it does not, treatment involves a multidisciplinary team that educates the family as well as the patient. The team can include a physician, nutritionist, dentist, psychologist or psychiatrist, and social worker. The first step is to treat any life-threatening conditions such as an obstructed intestine or high levels of lead in the blood. After that, any nutritional deficiencies are corrected. If an underlying mental health disorder exists along with pica, it is treated with appropriate therapies and/or medications.
Behavioral interventions are taught to both the family and the patient and are modified depending on the age of the patient and any disabilities or mental health disorders that the patient has. These interventions can include:
Why some people develop pica and others do not is unknown. The disorder cannot be prevented. In many developmentally normal children, pica disappears on its own after a few months. When it does not, it can and should be treated because if can lead to many undesirable health consequences.
See also Anemia, Bleeding, and Clotting • Autism Spectrum Disorder • Dietary Deficiencies • Intellectual Disability • Lead Poisoning • Malnutrition • Obsessive-Compulsive Disorder • Schizophrenia
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Young, Sera L. Craving Earth: Understanding Pica—The Urge to Eat Clay, Starch, Ice and Chalk. New York, Columbia University Press, 2011.
MedlinePlus. “Pica.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/ency/article/001538.htm (accessed March 7, 2016).
American Pregnancy Association. 1425 Greenway Dr., Irving, TX 75038 Toll-free: 800-672-2296. Website: http://americanpregnancy.org (accessed March 7, 2016).
* DSM-5 is the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, published by the American Psychiatric Association. This book is used by physicians in the United States to classify and diagnosis of mental conditions.
* feces, also called stool, is solid human or animal waste.
* endoscopy is a diagnostic procedure in which a tube with a light and a camera is inserted through the mouth, down the esophagus and into the stomach. It is used to visualize various digestive disorders.