Pica refers to a psychiatric disorder in which patients report a craving for and compulsive consumption of substances that are not food. Substances consumed include earth, clay, plaster, paint chips, string, hair, animal feces and stones 1.
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Epidemiology
Although the condition can present in any age group, most commonly pica has a childhood-onset. Often onset is in patients with neurodevelopmental disorders 2. Conditions such as obsessive-compulsive disorder and attention-deficit/hyperactivity disorder are frequently comorbid 2.
Clinical presentation
Diagnostic criteria for diagnosis of pica according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) states that the following four criteria must be met 3:
persistent eating of nonnutritive, nonfood substances over a period of at least 1 month
the eating of nonnutritive, nonfood substances is inappropriate to the developmental level of the individual
the eating behavior is not part of a culturally supported or socially normative practice
if the eating behavior occurs in the context of another mental disorder (e.g. intellectual disability (intellectual developmental disorder), autism spectrum disorder, schizophrenia) or medical condition (including pregnancy), it is sufficiently severe to warrant additional clinical attention
In some cases, pica only comes to the attention of clinicians due to complications such as intestinal obstruction/perforation, infections or poisoning 3. Dental complications such as caries, enamel erosion or abrasion, loss of vertical dimension occlusion and cracked teeth may also be present 2.
History and etymology
The word "pica" is derived from the Latin word, pīca, which means magpie 4. This is due to the bird's tendency to collect a variety of objects and the belief that it could eat anything. The condition was first documented by the Greek physician Hippocrates (460-370 BCE) in the fourth century BCE 4.