Caustics: Strong alkaline chemicals that destroy soft body tissues resulting in a deep, penetrating type of burn, in contrast to corrosives, that result in a more superficial type of damage via chemical means or inflammation. Caustics are usually hydroxides of light metals. SODIUM HYDROXIDE and potassium hydroxide are the most widely used caustic agents in industry. Medically, they have been used externally to remove diseased or dead tissues and destroy warts and small tumors. The accidental ingestion of products (household and industrial) containing caustic ingredients results in thousands of injuries per year.Burns, ChemicalEsophageal Stenosis: A stricture of the ESOPHAGUS. Most are acquired but can be congenital.Sodium Hydroxide: A highly caustic substance that is used to neutralize acids and make sodium salts. (From Merck Index, 11th ed)Esophagus: The muscular membranous segment between the PHARYNX and the STOMACH in the UPPER GASTROINTESTINAL TRACT.Dilatation: The act of dilating.Upper Gastrointestinal Tract: The segment of GASTROINTESTINAL TRACT that includes the ESOPHAGUS; the STOMACH; and the DUODENUM.Household Products: Substances or materials used in the course of housekeeping or personal routine.Endoscopy, Digestive System: Endoscopic examination, therapy or surgery of the digestive tract.