Broadening the perspective of pica: literature review.

Pica is an eating disorder that is manifested by a craving for oral ingestion of a given substance that is unusual in kind and or quantity. It is a long-standing practice that has far reaching implications for prevention and treatment--implications for public health as well as clinical personnel who work in settings where they have the potential for influencing health knowledge, attitudes, and behaviors of their patients. Pica practices also challenge researchers and social scientists whose work encompass development and refinement of models related to nutritional deficiencies. The body of literature on pica is so fragmented that it is difficult to find a precise summary of the knowns and unknowns about the condition. There is little consistency in defining pica, classifying substances ingested, identifying key characteristics of practicers, recommending treatment, or in projecting outcomes. This review presents a framework for understanding pica as a general practice, summarizes divergent reported hypotheses and conclusions, and illustrates that there is a need for more comprehensive studies of prevalence and incidence and use of deductive as well as inductive research processes.