Pica: Common but Commonly Missed

, , and , Department of Family Medicine, Wayne State University, Detroit.

J Am Board Fam Med. 2000;13(5) 

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The effects of pica have been classified into five groups:[4] (1) inherent toxicity, including direct toxic effects of substances such as lead or other heavy metals; (2) obstruction, such as may be seen in trichophagia (hair eating); (3) excessive calorie intake, generally related to amylophagia (starch eating); (4) nutritional deprivation, such as eating clay instead of nutritive foods; and (5) other, such as parasitic infections and dental injury (Table 2).

Other metabolic abnormalities associated with pica include zinc deficiency, as described above.[2] Hyperkalemia was noted in a renal failure patient who ate sandstone.[17] Ergun et al[18] explored the possibility of a relation between geophagia and liver damage, because early reports of a pica syndrome included hepatosplenomegaly. Of the 38 patients with pica in the Ergun et al report, none had liver abnormalities. In children, a common problem associated with pica is lead poisoning related to unintentionally eating lead-based paint chips or the soil surrounding a home painted with lead-based paint.[19] Helminthic infection, causing eosinophilia and gastrointestinal symptoms, has been described as well. In fact, in a study of Jamaican children with pica, worm infestation was found in more than 70%.[20]

Intestinal obstruction can be caused by pica, either as a result of numerous parasites[9] or more commonly trichobezoars.[21] Patients with trichobezoars are typically women younger than 30 years, most of whom do not have a psychiatric disorder. A summary of several clinical studies of pica is displayed in Table 3.


Discovery of pica behavior in a particular patient can be difficult. In the absence of complications that might signal such eating patterns, diagnosis depends on self-reporting. Patients are likely to underreport pica behavior because of embarrassment or because they are not aware that such behavior might be worth reporting. More often, the diagnosis is made when the patient has complications, such as anemia, lead poisoning, intestinal obstructions, or other metabolic conditions.[8] Even in patients who have these complications, the diagnosis could easily be missed without a high degree of suspicion. In a study of 38 cases of pica, certain clinical findings were frequent, such as anemia, splenomegaly, spoon nail, and growth retardation.18 Physicians should give patients suspected of pica behavior a thorough physical examination, looking for the above findings, and should obtain blood tests, such as complete blood count, peripheral smear for eosinophilia,[19] iron level, ferritin level, lead level, electrolytes, and liver function tests. Abdominal radiographs might be necessary to evaluate for intestinal obstructions from either bezoars or parasites. Stool samples can be used to rule out ova and parasites.[8] Even armed with all these tests, the diagnosis of pica requires that the patient (or parent of the patient) admit to the behavior, because all these clinical findings are nonspecific.

As described, recent reports have suggested a relation between pica and the spectrum of OCDs.[4,15] In adult and child patients with OCD symptomatology or features, it is likely that the compulsive eating of nonfood substances will be secretive and thus difficult to elicit as part of a dietary history. Physicians must ask directly about the ingestion of nonfood substances that are common to pica.

When evaluating children, parents should be interviewed about dietary habits and pica behaviors. An open discussion with the child about favorite foods, followed by specific questions about ingestion of nonfood substances, might aid in the diagnosis. If pica is suspected, but parents are unaware of such behaviors, the physician can ask them to keep an observational log of the child's solitary outdoor play. This log can reveal possible pica behaviors as well as give the physician some idea of the degree of parental involvement with the child. It might also help to rule out a pattern of neglect that has been speculated by some investigators to be associated with pica in children.[24]

If OCD (or impulse control) symptoms occur in an adult or child patient, an assessment of pica symptoms is advised. Similarly, patients with pica should be assessed for DSM-IV OCD and impulse control symptomatology (Table 4). OCD is characterized as obsessive risk avoidance, with ritualistic behaviors aimed at avoiding injury or illness. Impulse control disorders are typified as increased risk-seeking behaviors, with increasing tensions before the behavior and relief of tension and gratification after the behavior.[15]


Physicians must be prepared for cases of pica in their daily practice. Education about nutrition, along with iron therapy or transfusions, might be the first wave of intervention. Psychological counseling or behavior therapy can also be useful adjuncts. Behavioral interventions, such as reinforcement for eating from a plate or punishment for engaging in pica, have been effective in children with developmental disabilities.[25] Parents can be instructed to provide closer supervision of children during play and to child-proof their homes (eg, remove lead-based paints) and play environments (eg, remove sand boxes that contain animal feces). Although pica in adults and children tends to remit with time, physicians should treat the condition when it occurs and causes complications. Appropriate treatment first involves screening for comorbid conditions and complications, then possibly using a combination of psychotherapy and selective serotonin-reuptake inhibitors. Not all forms of pica are dangerous, and some might not require intervention. A high index of suspicion is required to make the diagnosis. Severe or recalcitrant cases could require referral to a mental health specialist.


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