The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines pica as eating nonnutritive, nonfood substances over a period of at least one month. The term is derived from "pica-pica," the Latin word for the magpie bird, because of the bird's indiscriminate gathering and eating a variety of objects for the sake of curiosity. For diagnosis, the behavior must persist for at least one month, not be in keeping with the child's developmental stage (and age cut off of 24 months or more is suggested by DSM V), and not be socially normative or culturally acceptable behavior. The nature of ingested items is variable, including but not limited to earth (geophagy), raw starches (amylophagy), ice (pagophagia), charcoal, ash, paper, chalk, cloth, baby powder, coffee grounds, and eggshells.

Although pica is seen in children, it is also a common eating disorder in patients who are intellectually impaired. In women, it is most often seen during pregnancy. In some parts of the world, the consumption of non-nutritive substances is culturally accepted. Pica usually occurs as an isolated disorder but there are instances when it may co-exist with schizophrenia, OCD, and trichotillomania.

It is important to understand that in order to diagnose pica, the individual must be at least 2 years of age. It is not unusual to notice that younger children are frequently eating nonnutritive substances.

Etiology

Many factors have been implicated in the etiology of pica; however, no direct causality has been established. Studies of psychological factors have reported an association between pica and stress, child neglect and abuse, and maternal deprivation. Iron deficiency anemia has also been implicated. Many population-based studies have found a low level of serum iron/ferritin (and other micronutrients) among patients with pica.. Despite this, studies conducted on substances consumed by pica patients failed to show increased iron bioavailability among these substances. This suggests that the idea that these cravings stem from a need for serum iron is an inadequate pathophysiological explanation for this phenomenon. Another proposed hypothesis that is gaining more attention is that pica for non-nutritive substances offers protection from harmful toxins during the most vulnerable stages of human cell replication and embryogenesis (childhood and pregnancy). The proposed mechanism of protection is binding to toxins and decreasing their intestinal absorption. In pagophagia, a Japanese study hypothesized that when a patient with anemia chews ice, it increases perfusion thus improving brain function. They contributed that to the activation of the dive reflex which would lead to peripheral vasoconstriction and an increase in central perfusion. Another explanation would be sympathetic activation which would also increase blood flow to the brain.

While the causes of Pica remain unknown, some of the risk factors for developing the disorder include the following:

• Stress

• Cultural factors

• Learned behavior

• Low socioeconomic status

• Underlying mental health disorder

• Nutritional deficiency

• Child neglect

• Pregnancy

• Epilepsy

• Familial psychopathology

History and Physical

A comprehensive history should be pursued along with caregiver interviews. The details of the exposure should be sought, including the type of substance, amount, duration of exposure, settings where behavior usually happens, the source of the substance, any co-ingestions, and symptoms of toxicity.

While, in most cases, the physical exam will be normal, one should look for signs of poisoning or complications. Bezoar ingestion could lead to obstruction and, possibly, ulceration and perforation. Lead poisoning manifests with neurological signs such as lethargy, headache, seizure, encephalopathy, cranial nerve palsy, and papilledema. Infectious agents that could present in clay include Toxocara and Ascaris. Signs of such parasitic infections include fever, cough, myocarditis and encephalitis, hepatomegaly, and visual disturbance.

Evaluation

Laboratory evaluation should be tailored according to the suspected substances ingested. Iron studies in patients with pica should be performed, especially in women who are pregnant, and children. Lead (in pica for paint and chalk) and zinc levels should be checked where appropriate. A basic metabolic panel should be obtained, especially in clay ingestion which can cause metabolic disturbances such as hypokalemia.

Imaging studies are usually required when patients have abdominal symptoms. This may include plain abdominal x-rays, barium studies, and endoscopy. In many cases, serial studies are needed to ensure that the substance has passed.

Treatment / Management

Primary prevention should be utilized to identify at-risk patients such as children who live in old homes with lead paint and woman who are pregnant. This could be achieved by screening for the condition among such populations. Strategies should be utilized to decrease exposure to the craved substance, such as reducing access or providing an appropriate substitute with a similar texture. Iron, zinc, and other nutrient supplementation should be provided when a deficiency is identified. Behavioral and aversive treatment might be effective in patients with mental disabilities. Differential reinforcement is a commonly used strategy to induce different patient responses to pica by redirecting the undesired behavior to other activities.

There are no medications specifically for the treatment of pica. While there are anecdotal reports about antipsychotic use to reduce pica behaviors, these drugs also cause constipation and other adverse effects.

Besides the removal of the substance from the environment, it is important to assess the cultural traditions and beliefs that promote pica behavior.

Differential Diagnosis

Careful screening should be performed for mental health problems in the setting of pica. Several psychiatric illnesses should be considered in the differential diagnosis including other eating disorders, schizophrenia and psychosis, autism and developmental delay in children, substance abuse and addiction.

Prognosis

Pica is usually a benign disorder if it is short term. In pregnant women and children, the condition spontaneously disappears without any sequelae. However, in individuals with intellectual impairment, it may persist for years. When Pica is long term it can result in bowel obstruction, bezoars, and even toxicity. Ingestion of dirt and paint can lead to infections and heavy metal toxicity. Many reports exist of people who have had to undergo surgery to relieve bowel obstruction, perforation, and ulcers.

Complications

The complications of pica can be categorized according to the type of substance ingested:

• Geophagia: Clay ingestion is a very common form of pica. It can lead to constipation, hypokalemia with myopathy, and nutritional deficiencies. Clay can also be a source of many infectious agents such as parasites. Lead poisoning can be a serious complication with clay ingestion.

• Pagophagia: Ice ingestion could lead to iron deficiency, especially during pregnancy. Other complications include tooth decay and sensitivity.

• Amylophagia: Excessive starch consumption has been associated with iron deficiency. It also can cause high blood sugar and obesity due to its high carbohydrate content.

• Other substances:Ingested materials can contain a wide variety of toxic contaminants such as lead, mercury, arsenic, fluoride, and many others. Exposure to such items can lead to a wide range of toxic effects such as lead poisoning. Lead poisoning could have dire consequences, particularly among women who are pregnant, and high levels can result in seizures.

Fetal Toxicity

Pica during pregnancy can have dire consequences on the growing fetus. There are case reports of intrauterine toxicity due to maternal pica. Lead poisoning has been implicated in long-term neurological disability. Maternal geophagy has been associated with childhood motor function delay.

Enhancing Healthcare Team Outcomes

Treatment of patients with pica should utilize an interprofessional team approach. A team consisting of a physician, psychiatrist/psychologist, behavioral therapist, social worker, and dietitian. Patients should be treated in a nonjudgmental manner, with particular attention to their cultural and social background.

Patient education is vital. Failure to educate patients on healthy eating habits is a common reason why pica can be prevalent in some populations. Parents need to be educated about the harms of ingesting nonnutritive substances by their children and the need for limiting such exposure. In some jurisdictions, landlords have to ensure that lead-based painting is removed. A dietary consult may benefit some families. Close follow up by the nurse practitioner may be required to ensure that the pica behavior is not continuing.

Clinicians should communicate with each other so that the same message is sent to the parent or caregiver.

What’s the Problem?

Pica behavior is the craving to eat nonfood items, such as dirt, paint chips, and clay. Some children, especially preschool children, exhibit pica behavior. Pica behavior is most common in 1- and 2-year old children and usually diminishes with age so that elementary-age children seldom exhibit pica behavior. Soil ingestion is the consumption of soil resulting from various behaviors including, but not limited to, mouthing objects or dirty hands, eating dropped food, and intentionally consuming soil. All children (and even adults) ingest small amounts of soil daily from these behaviors. The distinguishing factor for soil-pica is the recurrent ingestion of unusually high amounts of soil either intentionally by eating dirt or unintentionally from excessive mouthing behavior or eating dropped food. While the typical child might ingest 1/8 teaspoon soil daily (or about 100 to 200 milligrams), children with soil-pica behavior ingest about a teaspoon or more of soil daily (or about 1,000-5,000 mg or more per day).

Pica and specifically soil-pica is a public health issue that has gotten little attention because people do not realize that it can lead to significant exposure to chemicals. However, soil ingestion has already been shown to be a significant risk factor for increased blood lead levels (BLL) and for exposure to soil-transmitted parasites. Up to 20% of preschool children have soil-pica behavior, which parents may not notice since their preschool children may play unattended in the safety of their back yards.

In addition, pica behavior has also been observed in adults, and in particular pregnant women. In many cases of adult pica, the practice has cultural significance or is the result of craving during pregnancy. In some cases, the craving is due to a nutritional deficiency, such as iron-deficiency anemia.

An example of an element that may be found in soil is arsenic. Inorganic arsenic doesn’t degrade and binds to soil particles at the surface. Historically, repeated applications of arsenic-containing pesticides and herbicides may have increased arsenic levels in top soil to very high concentrations and can be a potential problem for children with soil-pica behavior. Pesticides containing arsenic are no longer commercially available. However, in many cases, soils were treated decades ago, yet the arsenic remains at the surface increasing the risk of contact from children’s play activities. If soil ingestion is suspected among children, it is important to know (1) the amount of soil ingested, (2) the frequency of ingestion, and (3) the type of material ingested.

Who’s at Risk?

Groups at risk of soil-pica behavior include children aged 6 years and younger as well as individuals of any age who are developmentally delayed. Soil-pica behavior is highest in 1- and 2-year-old children and declines as the children grow older.

Can It Be Prevented?

Parents and guardians must be responsible for closely monitoring young children and persons who have developmental delays to ensure that soil is not ingested. Additionally, proper hand-washing techniques must be employed after being outside and before eating to ensure that contaminants and parasites in soil do not pose any further threats through hand-to-mouth contact.

The Bottom Line

Soil-pica is the ingestion of soil which may lead to exposure to chemicals and has been shown to be a risk factor for exposure to lead and soil-transmitted parasites. Up to 20% of preschool children have soil-pica behavior, often consuming soil in their own backyards. Pica behavior can pose significant risks and should be minimized so that those at risk are not harmed by contaminants in the ground. Parents should monitor children when they are playing in the yard and should enforce hand-washing after playing outdoors and before eating.

Case Example

Arsenic Case Example

This scenario takes place in the mid-west (Omaha, NE, for example), which has alkaline soil and low rainfall, two factors that promote binding of arsenic to soil particles. In these conditions, arsenic will bind with the top few inches of soil, so the surface soil usually has the highest arsenic levels and concentrations decrease with depth. A preschool child develops nausea, stomach cramps, vomiting, sore throat, listlessness and mild diarrhea, so the mother takes the child to the emergency room. Doctors treat him for symptoms but are unable to identify a cause. The child is admitted overnight for observation and recovers. Two weeks later, mother and child are back in the hospital with the child experiencing the same symptoms. Again, the child is admitted overnight, recovers and is sent home. A week later, mother and child are back a third time with the child displaying the same symptoms. This time the doctor notices periorbital swelling (swelling around the eye socket). This reminds her of an incident in Japan in the 1950s when people who were exposed to arsenic by consuming contaminated soy sauce displayed the distinguishing characteristic of periorbital swelling that subsided shortly after exposure. The doctor tests the child for total arsenic in the urine and finds 500 ppb. Since the average total arsenic levels in urine is 7 ppb (and the 95th percentile for children is 47 ppb), this level is considered very high. The doctor explains that arsenic is excreted rapidly from the body via the urine and that the urine arsenic level from the previous day was probably much higher. The doctor asks the mother if the child has eaten any type of seafood within the last 3 days. Seafood will result in high arsenic levels, although arsenic in seafood, known as “fish arsenic” (arsenobetaine), is not toxic. The mother replies that the child has not eaten any seafood.

The doctor asks the mother about possible pesticide exposure, but she says that pesticides are kept behind child proof cabinets or in the free-standing locked garage that is used as a storage area. The doctor suspects “Munchhausen by proxy,” a condition where a parent or guardian will poison a child or relative so he/she will require diagnostic tests and hospitalization. Before she investigates this possibility, she asks the mother if the child has any unusual eating habits. The mother remembers catching him eating a cigarette butt about a year ago, but she reprimanded the child and has not seen the behavior since.

The doctor refers the child and mother to a case worker who visits the home to observe the home environment and the child’s behavior. The case worker watches the child playing in the back yard and notices that he is surreptitiously eating dirt. The mother is quite surprised at this behavior and very apologetic. The soil is then tested and found to contain 1,000 ppm of arsenic. The parents do not know how the arsenic got there but state that the house was built on the site of an old apple orchard that was owned by the child’s grandparents. In talking to the grandmother, they find that she regularly used a pesticide in the apple orchard. The doctors research the pesticide and discover that the main ingredient is arsenic trioxide. Remaining in the soil all these years, the arsenic has been causing the child’s symptoms.