An Update on Pica: Prevalence, Contributing Causes, and Treatment

Problems/complications
Serious medical consequences are associated with pica. Lead poisoning continues to be a hazard in young children. The persistence of hand-to-mouth movements in young children especially from the age of 18 to 36 months may result in the ingestion of lead-based paint.⁸ Whole blood lead levels greater than 25 mg/dL indicate that the child is in a contaminated environment.

Elevated blood levels of lead have multiple effects on cognition (including learning impairment and behavior), diminished attention span, and impulsive behaviors.¹⁵ Neurological complications of chronic lead poisoning may present as mental retardation, convulsive disorders, peripheral neuropathy, behavioral disturbance, or any combination thereof.³⁹

Special types of pica and their medical complications include paper pica, which can lead to mercury poisoning. The ingestion of soil or clay has been associated with soil-borne parasitic infections, and ingestion of contaminated substances can present a significant health hazard.⁴⁰ Behavioral problems in the developmentally disabled associated with pica include stereotypical behavior, hyperactivity, self-abuse, and food-related abnormal behaviors including eating off the floor and chewing objects.^41,42

Treatment
Reduction in exposure is the cornerstone of any treatment program. Treatment approaches are primarily preventive, educational, and directed toward modification of pica behavior (Table 3). In addition, iron supplementation has been seen to dramatically reverse pica in those patients whose clinical symptoms are more clearly coincident with iron deficiency from nutritional or covert medical causes.⁴³ Nutrient treatment of pica has been reported as early as the 10th century, when Avicenna added iron to wine as a treatment for earth eating.^1,23



Behavioral treatment approaches in pica involve careful observational analysis and the application of consistent contingent responses by a trained staff member. In a critical review of pica treatment, Albin⁴⁴ pointed out conceptual differences in the definition of pica: nonfood items ingested in contrast to eating food on the floor. He noted that use of experimental tactics such as baiting the patient and the absence of data about generalization and maintenance of improvement made comparative evaluation of different treatment techniques difficult. Furthermore, primarily developmental factors, particularly the perpetuation of a finger-feeding stage that interferes with the use of utensils in mentally handicapped persons, may be related to the persistence of pica.

Often, the control of pica in mentally handicapped adults with complicated histories presents a clinical problem that must be approached through individualized design and the presence of aversive but not harmful consequences. Several behavioral techniques have been used to diminish pica behavior in developmentally disabled patients in a residential setting. One paradigm of treatment consists of verbal reprimand setting, response interruption, generalization, and reward that results in discrimination training.