Pica
Synonyms and keywords: Pica syndrome, geophagia eating disorder, geophagy

# Overview

# Historical Perspective
- Pica is derived from the Latin word 'pica pica' which means magpie, a bird known for its behavior of gathering and eating almost everything.
- It was first documented in the 13th century in Latin work of Bartholomeus de Glanville, although the actual term was not used.
- The first time term Pica was mentioned in a medical context was in 1563 in a surgical work, An Excellent Treatise of Wounds made with Gonne Shot, by Thomas Gale, where pica was addressed in pregnant women and children.
- Historically, clay ingestion had been used for medical purposes probably due to its effect on gastrointestinal (GI) system. It was particularly suggested as a treatment of intestinal infection and spasm.

# Classification
Pica may be classified according to the name of the eaten substance; the most common types by far are geophagia and amylophagia:
- Acuphagia (sharp objects)
- Amylophagia (purified starch)
- Cautopyreiophagia (burnt matches)
- Coniophagia (dust, dirt)
- Coprophagia (feces)
- Emetophagia (vomit)
- Geomelophagia (raw potatoes)
- Geophagia (earth, soil, clay, chalk)
- Hyalophagia (glass)
- Lithophagia (stones)
- Metallophagia (metal)
- Mucophagia (mucus)
- Pagophagia (ice)
- Plumbophagia (lead, paint chips)
- Trichophagia (hair, wool, fibers)
- Urophagia (urine)
- Hematophagia (blood)
- Xylophagia (wood, paper)
- Hyalophagia (glass)
- Ryzophagia (raw rice)
- Sapophagia (soap)

# Pathophysiology
The exact pathogenesis of Pica is not fully understood. However, there are different theories on developing Pica:

## Nutritional Theory
- Children with anemia and low plasma zinc levels may develop Pica and crave for substances rich in the insufficient nutrients.
- Kaolinite, a clay mineral, which has negative surface charge commonly ingested in Pica and can absorb the ions with positive surface charge, such as iron and causes iron-deficiency anemia. 
- There is not enough evidence to determine whether Pica is the cause of nutritional deficiency or nutritional deficiency leads to Pica development. 

## Gastrointestinal Distress
Geophagia causes increase in gastrointestinal PH. This effect can soothe gastric pain and gastroesophageal reflux disease. It also results in reduction of bioavailability of pathogens and toxins in gastrointestinal tract, a phenomenon on which a hypothesis is based. The hypothesis states that non-nutritive substances bind to toxins and lead to less toxins absorption. This event occurs in the most vulnerable period of cell replication and growth (childhood and pregnancy) in order to protect the body from dangerous toxins.

## Neurological Theory
- Various human studies revealed that lesions in eating center of hypothalamus and anterior cingulate gyrus may lead hyperphagia and Pica especially in individuals with history of brain damage.
- Animal studies indicated that rats with iron deficiency anemia have fewer D2 receptors in the central nervous system (CNS). This proposes a theory stating that reduction of dopaminergic neurotransmission leads to development of Pica, and not the iron deficiency anemia.

## Psychiatric Theory
A hypothesis states that Pica can be attributed to obsessive-compulsive spectrum disorders because Pica-related behaviors are mostly involuntary, recurrent, and persistent to soothe the anxiety and distress, and resistance to stop the behaviors causes increased level of anxiety and distress. This hypothesis is supported by studies that have found that Pica has the same treatment as OCD, i.e selective serotonin reuptake inhibitors.

# Causes
The cause of Pica has not been identified. To review risk factors for the development of Pica, click here.

# Differentiating ((Page name)) from other Diseases
Pica must be differentiated from other psychiatric diseases including autism, schizophrenia, other eating disorders, developmental delay in children, substance abuse.

# Epidemiology and Demographics
- The prevalence and incidence of Pica is challenging to estimate due to several reasons such as: under-reporting the cases, cultural and social issues, different definition of Pica in studies.
- Pica is more common in pregnant women and young children.
- The incidence of Pica decreases with age. Studies show 20-30% of children who are between 1-6 years old have developed Pica.
- Boys are slightly more affected by Pica than girls.
- The majority of Pica cases are reported in Africa.

# Risk Factors
Common risk factors in the development of Pica include:
- Nutritional deficiency
- Pregnancy
- Stress
- Child abuse, child neglect, family problem, parental separation, low socioeconomic status
- Cultural factors
- Mental disorders
- Learning and developmental disability such as autistic spectrum disorder, attention-deficit hyperactivity disorder
- Epilepsy

# Screening
There is insufficient evidence to recommend routine screening for Pica.

# Natural History, Complications, and Prognosis
If left untreated, patients with Pica may progress to develop:
- Iron deficiency anemia especially during pregnancy. This complication may occur due to binding of clay particle to iron or acting as an ion exchanger resin.
- Lead poisoning 
- Parasite infection (e.g. ,toxocariasis, toxoplasmosis, ascariasis, giardiasis, cysticercosis)
- Electrolyte abnormalities such as zinc deficiency, hypokalemia, hyperkalemia, hyperphosphatemia and metabolic alkalosis.
- Constipation and intestinal obstruction, bleeding and perforation.
- Social stigmatization especially in children.
- Tooth decay and sensitivity.
- High blood sugar and obesity due to amylophagia.
- Maternal Pica may lead to neurological disability and delayed motor function in newborns.

# Diagnosis

## Diagnostic Study of Choice
The diagnosis of Pica is based on the criteria from Diagnosis and Statistical Manual of Mental Disorders (DSM-5), which include:
1.Person must have been eating non-nutritive nonfoods for at least one month.
2.This eating must be considered abnormal for the person's stage of development.
3.Eating these substances cannot be associated with a cultural practice that is considered normal in the social context of the individual.
4.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.

## History and Symptoms
Symptoms of Pica are variable and depend on the material which is ingested.
Physicians should seek the details of the exposure, including:
- the substance type,
- the amount of substance,
- duration of exposure,
- situations where behavior usually happens,
- any co-ingestions, and
- symptoms of toxicity

## Physical Examination
Patients with Pica usually appear normal. However, sings of poisoning and complications of the ingested substance should be sought:
- Ingestion of some substances may lead to bezoar formation and consequently, intestinal obstruction, ulceration, and perforation,
- Lead poisoning symptoms include:
lethargy,
headache,
seizure,
encephalopathy,
cranial nerve palsy,
papilledema,
cognitive impairment,
peripheral neuropathy,
abdominal pain and constipation,
lead-line at the junction of gums and teeth, and
developmental delay in children.
- lethargy,
- headache,
- seizure,
- encephalopathy,
- cranial nerve palsy,
- papilledema,
- cognitive impairment,
- peripheral neuropathy,
- abdominal pain and constipation,
- lead-line at the junction of gums and teeth, and
- developmental delay in children.
- Signs of parasitic infections (Toxocara and Ascaris) due to clay ingestion include:
fever,
cough,
myocarditis,
encephalitis,
hepatomegaly, and
visual disturbance.
- fever,
- cough,
- myocarditis,
- encephalitis,
- hepatomegaly, and
- visual disturbance.
- Malnourishment, especially in children
- Signs of iron deficiency anemia:
pallor,
easy fatigability,
poor appetite,
tachycardia and a soft ejection systolic flow murmur in severe cases.
- pallor,
- easy fatigability,
- poor appetite,
- tachycardia and a soft ejection systolic flow murmur in severe cases.
- Dental complications such as severe abrasion and tooth damages.

## Laboratory Findings
Laboratory findings consistent with the diagnosis of Pica include:
- CBC (anemia)
- Electrolyte and nutrient evaluation (zinc deficiency, hyperkalemia)
- Liver function test
- Stool exam for parasite infections
- Blood lead concentration

## Electrocardiogram
There are no ECG findings associated with Pica.

## X-ray
There are no x-ray findings associated with Pica. However, an x-ray may be helpful in the diagnosis of complications of Pica, which include lead lines at the metaphysis of long bones and foreign bodies in chest or abdominal x-ray.

## Echocardiography or Ultrasound
There are no echocardiography/ultrasound  findings associated with Pica. However, an ultrasound  may be helpful to reveal the location, size and the nature of the substance.

## CT scan
There are no CT scan findings associated with Pica.

## MRI
There are no MRI findings associated with Pica.

## Other Imaging Findings
There are no other imaging findings associated with Pica.

## Other Diagnostic Studies
There are no other diagnostic studies associated with Pica.

# Treatment

## Medical Therapy
The majority of cases of Pica are self-limited and require only supportive care.
Supportive therapy for Pica includes:
- nutrient supplements such as iron and zinc in case of deficiency.
- Behavioral therapy, psychotherapy and family counseling particularly in children.

## Surgery
Surgical intervention is not recommended for the management of Pica Unless it causes severe obstruction or perforation.

## Primary Prevention
Effective measures for the primary prevention of Pica include:
- Identifying high- risk populations such as pregnant women and children who live in old house with lead paint,
- Nutrition education in at-risk populations about the danger and consequences of Pica,
- Educating parents to supervise their children and make their home and environment safe.

## Secondary Prevention
There are no established measures for the secondary prevention of pica.