Pediatric Mercury Toxicity Treatment & Management

The general management measures in Minamata disease are the same as in those of any other toxicologic exposure. After initial assessment and stabilization of the patient's condition, eliminate the patient's exposure to the source of the mercury. Provide general supportive measures, including monitoring, the performance of baseline laboratory studies, and the creation of a differential diagnosis.

Once the neurologic consequences of Minamata disease appear, they are, unfortunately, irreversible. The goal of medical management in Minamata disease is to reduce the total body burden of mercury and minimize further damage.

• Because mercury binds to the body's ubiquitous cellular sulfhydryl groups, chelating agents should be administered early in treatment. These agents are thought to competitively bind the mercury by using its thiol groups. Currently, the best agent for the treatment of Minamata disease is 2,3-dimercaptosuccinic acid (DMSA). Its toxicity is low, and animal trials have shown that it is superior to older chelating agents such as dimercaprol (BAL) and d-penicillamine (DPCN). Even in cases of inorganic mercuric salt exposure, DMSA is preferred over DPCN.
• GI decontamination may be useful only in acute recent ingestions. The absorption of organic forms of mercury, such as methyl mercury, is more than 90% in the GI tract. Inorganic mercuric salts (eg, mercuric chloride) are absorbed at a substantially lower rate of about 10%.

  • Because of the high propensity for neurologic impairment, patients with acute mercury ingestion should undergo gastric lavage with solutions that contain proteins such as those from milk or egg whites.
  • In addition, activated charcoal should be administered although it does not absorb heavy metals well in general. However, a 1948 in vitro study demonstrated that 1 g of activated charcoal could bind 800 mg of mercuric chloride.^[5]
• Whole bowel irrigation, along with the administration of polyethylene glycol solution, has been shown to be useful in clearing residual mercury, as depicted on serial abdominal radiography.
• Hemodialysis is not effective in reducing the total-body mercury burden. However, acute renal failure can occur after inorganic mercuric salt ingestion, and hemodialysis may become necessary.

Surgery does not have a role in the treatment of Minamata disease; however, in other forms of mercury exposure, surgical intervention is occasionally warranted.

Rare cases of mercury implantation into the soft tissue either accidentally or in suicide attempts are reported. In all such cases, early definitive surgical excisions of the mercury deposits result in good outcomes with minimal toxicity.

Clinical toxicologists are available for consultation through many regional poison control centers.

Consultation with a toxicologist is advised in any patient in whom a significant toxicologic exposure to mercury or any other toxin is suspected.

In some studies, the levels of mercury in shark, swordfish, and large tuna steaks exceeded the Food and Drug Administration (FDA) safety limit of 1 part per million; however, most other fish sold in the United States have clearly lower levels of approximately 0.3 part per million.

Because of the high morbidity and mortality rates associated with methyl mercury poisoning, especially in utero, pregnant women and nursing mothers should avoid consuming larger fish because their mercury concentrations tend to be higher than those in smaller fish.