Pica

Pica is a psychological disorder characterized by an appetite for substances that are largely non-nutritive, such as ice, soap, hair, paper, metal, soil, stones, glass, or chalk. The term pica originates in the Latin word for magpie (picave), a bird that is famed for its unusual eating behaviors, where it is known to eat almost anything. Here are types of cravings someone with pica may have:

• acuphagia (sharp objects)
• amylophagia (starch)
• cautopyreiophagia (burnt matches)
  

  Figure 1. Consuming non-nutritional substances like rocks can lead to surgical emergencies.

• coniophagia (dust)
• coprophagia (feces)
• emetophagia (vomit)
• geomelophagia (raw potatoes)
• geophagia (earth, soil, or clay)
• hyalophagia (glass)
• lithophagia (stones)
• mucophagia (mucus)
• pagophagia (ice)
• plumbophagia (lead)
• trichophagia (hair, wool, and other fibers)
• urophagia (urine)
• hematophagia (vampirism) (blood)
• xylophagia (wood or derivates of wood such as paper)

According to the DSM-5 criteria, for these actions to be considered pica, they must persist for more than one month at an age when eating such objects is considered developmentally inappropriate, not part of a culturally sanctioned practice, and sufficiently severe to warrant clinical attention. Pica may lead to intoxication in children, which can result in an impairment of both physical and mental development. In addition, it may cause surgical emergencies to address intestinal obstructions, 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[failed verification] are strongly linked to pica as a form of comfort.

Pica is most commonly seen in pregnant women, small children, iron- and zinc-deficient children, malnourished children, and people with intellectual disabilities.^[1]

Children eating painted plaster containing lead may suffer brain damage from lead poisoning. A similar risk exists from eating soil near roads that existed before the phase-out of tetraethyllead or that were sprayed with oil (to settle dust) contaminated by toxic PCBs or dioxin. In addition to poisoning, a much greater risk exists of gastrointestinal 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 animals such as dogs and cats.

Causes

According to the DSM-5, mineral deficiencies are occasionally associated with pica, but biological abnormalities are rarely found. People practicing forms of pica, such as geophagy, pagophagy, and amylophagy, (soil, ice, or starches) 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 be associated with anemia or low hemoglobin. Practicing pagophagy and amylophagy is more highly associated with anemia. Additionally, children and pregnant women may be more likely to have anemia or low hemoglobin relative to the general population. More recently, cases of pica have been tied to the obsessive-compulsive spectrum, and a move has arisen to consider OCD as the cause of pica.

If nutritional deficits and lead exposure are ruled out, then pica is likely brought on by emotional distress. In these instances, the child may also display abnormal behaviors such as using strange language, engaging in strange play, or having relationship issues with other peers.^[2]

Diagnosis

No single test confirms pica, but 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 healthcare provider should test for infection if the patient has been eating contaminated soil or animal waste.

The DSM-5 posits four criteria that must be met for a person to be diagnosed with pica:^[3]

• A person must have been eating non-nutritive nonfoods for at least one month.
• This eating must be considered abnormal for the person’s stage of development.
• Eating these substances cannot be associated with a cultural practice that is considered normal in the social context of the individual.
• For people who currently have a medical condition (e.g., pregnancy) or a mental disorder (e.g., autism spectrum disorder), the action of eating non-nutritive nonfoods should only be considered pica if it is dangerous and requires extra medical investigation or treatment on top of what they are already receiving for their pre-existing condition.

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%-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%).^[4] 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 their mouths. 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  ten to 33% of the population.

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 through iron supplement by 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.

Figure 2. A favorite stuffed animal or toy can be used as a reward to reinforce healthy eating behaviors.

A clinician will look at likely causes of pica to help determine the best treatment method. For example, if pica is a result of social inattention, a treatment strategy could involve ignoring the pica and giving praise and attention for other desirable behaviors. 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 nonmedication techniques might include other ways for oral stimulation such as chewing gum or eating popcorn.

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.^[5] These treatments may involve using positive reinforcement for healthy eating behavior. Some methods 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). Success with treatment is 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 the following:

• presentation of attention, food, or toys, not contingent on pica being attempted
• differential reinforcement with positive reinforcement if pica is not attempted and consequences if pica is attempted
• discrimination training between edible and inedible items with negative consequences if pica is attempted
• visual screening with eyes covered for a short time after pica is attempted
• aversive presentation contingent on pica being attempted:
  • oral taste (e.g., lemon)
  • smell sensation (e.g., ammonia)
  • physical sensation (e.g., water mist in face)
• physical restraint
  • self-protection devices that prohibit placement of objects in the mouth
  • brief restraint contingent on pica being attempted
  • time-out contingent on pica being attempted
  • overcorrection with attempted pica resulting in required washing of self, disposal of nonedible objects, and chore-based punishment
  • negative practice (inedible object held against patient’s mouth without allowing ingestion)