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INTRODUCTION AND EPIDEMIOLOGY
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Caustics are substances that cause both functional and histologic damage on contact with body surfaces. Many household and industrial chemicals have caustic potential. Caustics are broadly classified as alkalis (pH >7) or acids (pH <7). In developed nations, increased education and product regulation (especially of acids) have decreased morbidity and mortality from caustic exposures in both adults and children. However, in underdeveloped parts of the world, exposure to caustics remains a significant problem.1,2,3,4 The challenges to exposure prevention and patient care include relative lack of childproof containers, easy and unregulated access to highly corrosive substances, cultural-specific propensities to ingest caustics in suicide attempts, sheer high volume of cases, delays to care in rural settings, malnutrition, financial resources of hospitals and families to provide the services needed, and poor follow-up.4 Alkaline ingestions predominate in the developed world,5 whereas acid ingestions are more common in developing countries.6
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Caustic exposures tend to fall into three distinct groups: (1) intentional teen or adult ingestions with suicidal ideation7; (2) unintentional ingestions (the majority of which are by curious children in the toddler age group)8; and (3) other incidental, often occupational or industrial contact exposures. The majority of reported exposures are unintentional or accidental, but although less frequent, intentional ingestions account for the majority of serious injuries.1 The geographic variation in caustic ingestion circumstances, such as involved substances, intention, age of the patient, and extent of evaluation, make it difficult to create encompassing recommendations or a consensus approach.4,9,10
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Many chemicals used in industry have caustic potential (Table 200-1). Household caustics are often less concentrated forms of industrial strength cleansers.
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The degree to which a caustic substance produces tissue injury is determined by a number of factors: pH, concentration, duration of contact, volume present, and titraTable acid or alkaline reserve. Acids tend to cause significant injuries at a pH <3 and="" alkalis="" at="" a="" ph="">11. The physical properties of the product formulation (i.e., liquid, gel, granular, or solid) can influence the nature of the contact with the tissue. Following ingestion, solid or granular caustics often injure the oropharynx and proximal esophagus, whereas liquid alkali ingestions are characterized by more extensive esophageal and gastric ...