Abstract

Pica is characterized by an appetite for substances that are largely non-nutritive, such as ice (pagophagia); hair (trichophagia); paper (xylophagia); drywall or paint; metal (metallophagia); stones (lithophagia) or soil (geophagia); glass (hyalophagia); or feces (coprophagia); and chalk. According to DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) criteria, for these actions to be considered pica, they must persist for more than one month at an age where eating such objects is considered developmentally inappropriate, not part of culturally sanctioned practice and sufficiently severe to warrant clinical attention. It can lead to intoxication in children, which can result in an impairment of both physical and mental development. In addition, it can also lead to surgical emergencies due to an intestinal obstruction as well as more subtle symptoms such as nutritional deficiencies and parasitosis. Pica has been linked to other mental and emotional disorders. Stressors such as emotional trauma, maternal deprivation, family issues, parental neglect, pregnancy, and a disorganized family structure are strongly linked to pica as a form of comfort.

Pica is most commonly seen in pregnant women, small children, and those with developmental disabilities such as autism. Children eating painted plaster containing lead may suffer brain damage from lead poisoning. There is a similar risk from eating soil near roads that existed before tetraethyllead in petrol was phased out (in some countries) or before people stopped using contaminated oil (containing toxic PCBs or dioxin) to settle dust. In addition to poisoning, there is also a much greater risk of gastro-intestinal obstruction or tearing in the stomach. Another risk of eating soil is the ingestion of animal feces and accompanying parasites. Pica can also be found in other animals and is commonly found in dogs.

Signs and symptoms

Pica is the consumption of substances with no significant nutritional value such as soil, soap or ice. Subtypes are characterized by the substance eaten:

This pattern of eating should last at least one month to fit the diagnosis of pica.

Signs and symptoms | Complications

Complications may occur due to the substance consumed. For example, lead poisoning may result from the ingestion of paint or paint-soaked plaster, hairballs may cause intestinal obstruction and "Toxoplasma" or "Toxocara" infections may follow ingestion of feces or dirt.

Causes

According to the DSM 5, mineral deficiencies are occasionally associated with pica; however, biological abnormalities are rarely found in individuals with pica. People practicing forms of pica, such as geophagy, pagophagy and amylophagy, are more likely anemic, have low hemoglobin concentration in their blood, lower levels of red blood cells (hematocrit), or have lower plasma zinc levels. Specifically, practicing geophagy is more likely to associated with anemia or low hemoglobin. Practicing pagophagy and amylophagy were more highly associated with anemia. Additionally, being a child or pregnant woman practicing pica was associated with higher chance of being anemic or having low hemoglobin relative to the general population. More recently, cases of pica have been tied to the obsessive–compulsive spectrum, and there is a move to consider OCD in the cause of pica. However, pica is currently recognized as a mental disorder by the widely used "Diagnostic and Statistical Manual of Mental Disorders" (DSM-IV). Sensory, physiological, cultural and psychosocial perspectives have also been used by some to explain the causation of pica. It has been proposed that mental-health conditions, such as obsessive-compulsive disorder (OCD) and schizophrenia, can sometimes cause pica.

However, pica can also be a cultural practice not associated with a deficiency or disorder. Ingestion of kaolin (white clay) among African-American women in the US state of Georgia shows the practice there to be a DSM-IV "culture-bound syndrome" and "not selectively associated with other psychopathology". Similar kaolin ingestion is also widespread in parts of Africa. Such practices may stem from health benefits such as the ability of clay to absorb plant toxins and protect against toxic alkaloids and tannic acids.

Diagnosis

There is no single test that confirms pica. However, because pica can occur in people who have lower than normal nutrient levels and poor nutrition (malnutrition), the health care provider should test blood levels of iron and zinc.

Hemoglobin can also be checked to test for anemia. Lead levels should always be checked in children who may have eaten paint or objects covered in lead-paint dust. The health care provider should test for infection if the person has been eating contaminated soil or animal waste. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, posits four criteria that must be met for a person to be diagnosed with Pica:

Diagnosis | Differential diagnosis

In individuals with autism, schizophrenia, and certain physical disorders (such as Kleine-Levin syndrome), nonnutritive substances may be eaten. In such instances, pica should not be noted as an additional diagnosis.

Treatment

Treatment for pica may vary by patient and suspected cause (e.g., child, developmentally disabled, pregnant or psychogenic) and may emphasize psychosocial, environmental and family-guidance approaches, (iron deficiency) may be treatable though iron supplement through dietary changes. An initial approach often involves screening for and, if necessary, treating any mineral deficiencies or other comorbid conditions. For pica that appears to be of psychogenic cause, therapy and medication such as SSRIs have been used successfully. However, previous reports have cautioned against the use of medication until all non-psychogenic causes have been ruled out.

Looking back at the different causes of pica related to assessment, the clinician will try to develop a treatment. First, there is pica as a result of social attention. A strategy might be used of ignoring the person’s behavior or giving them the least possible attention. If their pica is a result of obtaining a favorite item, a strategy may be used where the person is able to receive the item or activity without eating inedible items. The individual’s communication skills should increase so that they can relate what they want to another person without engaging in this behavior. If pica is a way for a person to escape an activity or situation, the reason why the person wants to escape the activity should be examined and the person should be moved to a new situation. If pica is motivated by sensory feedback, an alternative method of feeling that sensation should be provided. Other non-medication techniques might include other ways for oral stimulation such as gum. Foods such as popcorn have also been found helpful. These things can be placed in a “Pica Box” that should be easily accessible to the individual when they feel like engaging in pica.

Behavior-based treatment options can be useful for developmentally disabled and mentally ill individuals with pica. Behavioral treatments for pica have been shown to reduce pica severity by 80% in people with intellectual disabilities. These may involve using positive reinforcement normal behavior. Many use aversion therapy, where the patient learns through positive reinforcement which foods are good and which ones they should not eat. Often treatment is similar to the treatment of obsessive compulsive or addictive disorders (such as exposure therapy). In some cases treatment is as simple as addressing the fact they have this disorder and why they may have it. A recent study classified nine such classes of behavioral intervention: Success with treatment is generally high and generally fades with age, but it varies depending on the cause of the disorder. Developmental causes tend to have a lower success rate.

Treatment techniques include:

Epidemiology

The prevalence of pica is difficult to establish because of differences in definition and the reluctance of patients to admit to abnormal cravings and ingestion, thus leading to the prevalence recordings of pica among at-risk groups being in the range of 8% and 65% depending on the study. Based on compiled self-report and interview data of pregnant and postpartum women, Pica is most prevalent geographically in Africa, with an estimated prevalence of 44.8%, followed by North and South America (23.0%) and Eurasia (17.5%). Factors associated with Pica in this population were determined to be anemia and low levels of education, both of which are associated with low socioeconomic backgrounds. Two studies of adults with intellectual disability living in institutions found that 21.8% and 25.8% of these groups suffered from pica.

Prevalence rates for children are unknown. Young children commonly place non-nutritious material into the mouth. This activity occurs in 75% of 12-month-old infants, and 15% of two-to-three-year-old children.

In institutionalized children with mental retardation, pica occurs in 10–33%.

History

The condition currently known as Pica was first described by Hippocrates. Prior to the elimination of the category of “feeding disorders in infancy and early childhood”, which is where pica was classified, from the DSM 5, pica was primarily diagnosed in children. However, since the removal of the category, psychiatrists have started to diagnose pica in people of all ages.

The term pica originates in the Latin word for "magpie", a bird that is famed for its unusual eating behaviors, where it is known to eat almost anything. In 13th-century Latin work, pica was referenced by the Greeks and Romans; however, it was not addressed in medical texts until 1563.

In the southern United States in the 1800s, geophagia was a common practice among the slave population. Geophagia is a form of pica in which the person consumes earthly substances such as clay, and is particularly prevalent to augment a mineral-deficient diet. Noteworthy is the fact that Kaolin was consumed by west Africans enslaved in the South-eastern United States, particularly the Georgia belt, due to the anti-diarrheal qualities in the treatment of dysentery and other abdominal ailments. The practice of consuming Kaolin rocks was thereafter studied scientifically, the results of which led to the subsequent pharmaceutical commercialization of Kaolinite, the clay mineral contained in Kaolin. Kaolinite became the active ingredient in drugs like Kaopectate and Pepto-Bismol, although the formulations have since found additional active ingredients to replace Kaolinite.

Research on eating disorders from the 16th century to the 20th century suggests that during that time in history, pica was regarded more as a symptom of other disorders rather than its own specific disorder. Even today, what could be classified as pica behavior is a normative practice in some cultures as part of their beliefs, healing methods, or religious ceremonies.

Other animals

Unlike in humans, pica in dogs or cats may be a sign of immune-mediated hemolytic anemia, especially when it involves eating substances such as tile grout, concrete dust, and sand. Dogs exhibiting this form of pica should be tested for anemia with a CBC or at least hematocrit levels. Although several theories have been proposed by experts for causes of pica in animals, there is insufficient evidence to prove or disprove any of them.