Poisoning can be caused by accidental administration of large amounts, excessive medical use or long-term application of bismuth. Pediatric bismuth poisoning (bismuthpoisoning) is mostly caused by the application of large amounts of bismuth subnitrate when treating diarrhea. Due to the role of intestinal bacteria, bismuth subnitrate can be oxidized to nitrite, so there can be symptoms of bismuth and nitrite double poisoning. The lethal dose of oral bismuth subnitrate in children is about 3~5g, and excessive intravenous or intramuscular injection of soluble bismuth salts can lead to acute poisoning. Insoluble bismuth salts (such as bismuth subcarbonate, etc.) are often internal drugs or topical preparations for the treatment of gastrointestinal diseases, and although they are absorbed in small amounts, they can lead to bismuth poisoning if applied in large amounts or for a long time. If a lactating woman applies bismuth cod liver oil several times due to nipple rupture, the infant may be poisoned by sucking in a large amount. For those who are allergic to bismuth salts, fever, rash, acute hemolysis, and occasionally exfoliative dermatitis may occur after intramuscular injection. How to check the symptoms of bismuth salt allergy? I. Clinical manifestations Acute poisoning mainly due to oral entry, sick children can have nausea, vomiting, salivation, pain in tongue and throat, abdominal pain, diarrhea, black feces with blood, and skin and mucous membrane bleeding, headache, cramps, etc. Due to liver and kidney damage, it may lead to hepatomegaly, jaundice, protein and tubular type in urine, and even acute liver and kidney failure. Application of large amount of bismuth subnitrate can simultaneously cause symptoms of nitrite poisoning, such as dizziness, red face, rapid pulse, chest pressure, dyspnea, and cyanosis due to methemoglobinemia; in severe cases due to heart and blood vessel paralysis, lower blood pressure and shock can occur. The prodromal symptoms of encephalopathy caused by bismuth subgallate, bismuth carbonate and bismuth silicate poisoning include headache, insomnia and mental abnormalities; later, obvious encephalopathy symptoms may occur suddenly, such as mental confusion, muscle tonicity, motor disorders, dysarthria, hallucinations and convulsions. For those who are allergic to bismuth salts, fever, rash, acute hemolysis, and occasionally exfoliative dermatitis may occur after intramuscular injection. Long-term application of bismuth can cause polyneuritis, stomatitis, gingival swelling, pigmentation of oral mucosa and black lines on gums. The patient’s x-ray of the long bone end can be seen as a white band, similar to that seen in lead poisoning cases. Laboratory examination 1. Blood measurement: Simple measurement methods can be used, such as (1) addition and subtraction method: take 1-2 drops of the patient’s blood, dilute it with 3-4ml of distilled water, add 1-2 drops of 10% hydroxide solution, mix well, when the COH in blood increases, the blood remains light red after adding alkali Unchanged, the normal blood is green, this test is positive only when the concentration is up to 50%. (2) Spectroscopic examination method: take several drops of blood, add 10ml of distilled water, and examine with spectroscopy to see the special absorption band. 2.Electroencephalography: diffuse low amplitude slow waves were seen, which paralleled the progression of hypoxic encephalopathy. 3.CT examination of the head: pathological hypodensity areas in the brain were seen in bismuth poisoning.