What is Iron Poisoning?

Iron poisoning is also called hemochromatosis. Hemochromatosis is divided into primary hemochromatosis and secondary hemochromatosis. The etiology of primary hemochromatosis is unknown. It is an autosomal dominant inheritance, which may be caused by abnormal absorption of iron in the intestinal mucosa, resulting in excessive iron absorption. Secondary patients due to thalassemia, active bone marrow hematopoiesis, repeated blood transfusions, excessive intake of iron-rich foods, drinking, drugs, nutritional deficiency, etc. cause damage to intestinal epithelial cells. Iron is easily absorbed and stored in tissues. Normal iron in the body is about lg. Symptoms only occur when 15 to 50 g of iron is accumulated.

Basic Information

Causes of iron poisoning

Iron poisoning is mostly caused by ingestion of excess ferrous sulfate. Young infants can be severely poisoned and even die due to oral administration of 40 mg to 1.5 g of ferrous sulfate; older children can die from poisoning by accidentally taking 10 to 15 sugar-coated ferrous pills (0.3 g each); Acidic fruits cause iron poisoning. Severe poisoning can occur with injections of iron preparations in excess.

Clinical manifestations of iron poisoning

The process of iron poisoning by mistake taking a large amount of iron can be divided into five phases:

1. After 30 minutes to 2 hours of ingestion of iron, local necrosis and bleeding occurred due to the irritating effect of iron on the gastrointestinal mucosa, leading to hemorrhagic gastroenteritis. Clinical manifestations: nausea, vomiting, abdominal pain, diarrhea, vomiting blood, bloody stools, and severe hypotension, shock, and coma can occur. This period lasts about 4 to 6 hours.

2. The next 2 to 6 hours are asymptomatic, and the patient's appearance is better. At this time, iron accumulates in mitochondria and various organs.

3. About 12 hours after oral administration of a large amount of iron, hypoglycemia and metabolic acidosis occur due to cell damage caused by iron. At the same time, fever, increased white blood cell count, and coma may occur. At this time, the child develops delayed shock. Serum iron can be as high as 89.5 mol / L (500 g / dl) or more.

4. Hepatic and renal damage occurred 2 to 4 days after oral administration of iron, and hepatomegaly, jaundice, abnormal liver function, and liver failure occurred. Hematuria, protein and cast in urine.

5. After taking iron for 2 to 4 weeks, it often remains because of scar formation. If a large amount of iron is taken orally for a long period of time, it may cause hemosiderinosis in the lungs, liver, kidneys, heart, pancreas, etc., and may cause embolic lesions and fibrosis.

Diagnosis of iron poisoning

According to the typical skin pigmentation, the liver and spleen are swollen, and the blood sugar is increased, and the general diagnosis is not difficult. However, laboratory data are still needed to confirm the diagnosis. If the plasma iron needs to exceed 35.8 mol / L, the plasma ferritin iron-binding saturation should exceed 50%, and skin lesion biopsy should see a large number of heme-containing particles and iron staining in the dermis. And an excess of urobilinogen, the Rous test found iron-containing cells in urine sediment.

Differential diagnosis of iron poisoning

It is distinguished from secondary hemosiderinosis caused by repeated blood transfusions. Although the disease has similar pigmentation, there is no fibrosis of the liver and pancreas, and clinical diabetes is rare. Although hepatolenticular degeneration has similar symptoms to this disease, it has golden brown pigmented rings around the corneal limbus, and has a series of neurological symptoms such as limb tremor, increased muscle tone, decreased voluntary movement, and lack of facial expression. . The disease should be distinguished from Addison's disease, brown yellow disease, silver deposit disease, arsenic melanosis and porphyria.

Iron poisoning complications

Gastrointestinal bleeding

Gastrointestinal bleeding may occur due to esophageal varices, and the incidence of hepatocellular carcinoma is 29%. This malignant complication only occurs in patients with cirrhosis. Compared with other types of liver cirrhosis, more liver cancer occurs in this disease. This type of liver cancer is often a multicentric nodule, rather than a single large mass, and there is no large amount of alpha-fetoprotein released into the blood. When a percutaneous liver biopsy is performed, a small spot of liver cancer may result in a negative result.

2. Cardiac complications

It can occur within a few days when sudden heart failure and / or arrhythmias occur, so those with evidence of cardiac involvement should be treated as an emergency. Alcoholics increase the risk of heart disease.

3. Bacterial peritonitis

If acute severe abdominal pain, bloating and shock occur, bacterial peritonitis is often complicated, and this disease is a serious fatal complication.

4. Other tumors

In addition to liver cancer, this disease can be complicated by other tumors, and the second tumor is mostly advanced patients. Other tumors include bladder cancer, ileum cancer, colon cancer, prostate cancer, etc. It has been reported that tumors do not appear until at least 7 years after the removal of excess iron.

5. Diabetes and joint disease

It is also the most common complication of this disease. It appears during the onset of disease and should be actively treated early.

Iron poisoning treatment

For sick children who accidentally take a lot of iron, give a lot of raw egg white, milk, etc. to promote the formation of ferritin complex, and use spit root syrup to induce vomiting, followed by gastric lavage with 2% to 5% sodium bicarbonate solution and leave it after washing Partially in the stomach, iron salts are converted into insoluble ferrous carbonate, and salt laxatives can be taken orally. If it is taken by mistake for more than 30 minutes, it is not advisable to induce vomiting to prevent perforation of the gastric mucosa corroded by the iron agent. When bleeding occurs, the gastric lavage should be stopped or repeated lavage with a small amount of liquid. There is still a large amount of iron agent in the stomach after gastric lavage. Internal gastrotomy should be considered to remove iron pills. In severe poisoning, hemodialysis or peritoneal dialysis can be used to exchange blood, which can reduce plasma iron, which can be used as appropriate in infants and young children.

Iron poisoning prevention

Although iron is an essential trace element for the human body, excessive intake of iron will cause chronic or acute iron poisoning, leading to liver cirrhosis and pancreatic fibrosis. The early manifestations of acute iron poisoning are nausea, vomiting, convulsions, gastrointestinal bleeding, etc .; if the iron is excessive, shortness of breath, tachycardia, hypoglycemia, irritability, convulsions, drowsiness, shock, and coma.