Clinical Spectrum of Mercury Poisoning in India: Case-series from a Poison Control Center.

BACKGROUND: Mercury is a naturally occurring heavy metal that finds wide application in industrial and household settings. It exists in three chemical forms which include elemental (Hg0 ), inorganic mercurous (Hg+) or mercuric (Hg++) salts, and organic compounds. All forms are highly toxic, particularly to the nervous, gastrointestinal, and renal systems. Common circumstances of exposure include recreational substance use, suicide or homicide attempts, occupational hazards, traditional medicines, and endemic food ingestions as witnessed in the public health disasters in Minamata Bay, Japan and in Iraq. Poisoning can result in death or long-term disabilities. Clinical manifestations vary with chemical form, dose, rate, and route of exposure. AIMS AND OBJECTIVES: To summarize the incidence of mercury poisoning encountered at an Indian Poison Center and use three cases to highlight the marked variations observed in clinical manifestations and long-term outcomes among poisoned patients based on differences in chemical forms and routes of exposure to mercury. MATERIALS AND METHODS: A structured retrospective review of the enquiry-database of the Poison Information Center and medical records of patients admitted between August 2019 and August 2021 in a tertiary care referral center was performed. All patients with reported exposure to mercury were identified. We analyzed clinical data and laboratory investigations which included heavy metal (arsenic, mercury, and lead) estimation in whole blood and urine samples. Additionally, selected patients were screened for serum voltage-gated potassium ion channels (VGKC)- contactin-associated protein-like 2 (CASPR2) antibodies. Three cases with a classical presentation were selected for detailed case description. RESULTS: Twenty-two cases were identified between August 2019 and August 2021. Twenty (91%) were acute exposures while two (9%) were chronic. Of these, three representative cases have been discussed in detail. Case 1 is a 3.5-year-old girl who was ought to the emergency department with suspected elemental-mercury ingestion after biting a thermometer. Clinical examination was unremarkable. Chest and abdominal radiography revealed radiodense material in the stomach. Subsequent serial radiographs documented distal intestinal transit of the radiodense material. The child remained asymptomatic. This case exemplifies the largely nontoxic nature of elemental mercury ingestion as it is usually not absorbed from the gastrointestinal tract. Case 2 is a 27-year-old lady who presented with multiple linear nodules over both upper limbs after receiving a red intravenous injection for anemia. Imaging revealed metallic-density deposits in viscera and bones. Nodular biopsy was suggestive of mercury granulomas. A 24-hour urine mercury levels were elevated. She was advised chelation therapy with oral dimercaptosuccinic acid (DMSA). Case 3 is a 22-year-old lady who presented with acrodynia, neuromyotonia, tremulousness, postural giddiness, tachycardia, and hypertension for 2 months, associated with intractable, diffuse burning pain over the buttocks and both lower limbs, 1 month after completing a 3-week course of traditional medications for polycystic ovarian syndrome. A 24-hour urine normetanephrine levels and mercury levels were markedly elevated. Serum anti-VGKC antibodies were present. She was treated with glucocorticoids and oral DMSA with a favorable clinical response. CONCLUSIONS: The clinical manifestations of mercury toxicity are highly variable depending on the source, form, and route of mercury exposure and are related to its toxicokinetics.

Characteristics, Treatment, and Prognosis of Elemental Mercury Intoxication in Children: A Single-Center Retrospective Study.

OBJECTIVES: Mercury exposure is common and can be toxic, especially in children. Children are often drawn to elemental mercury because of its density, color, and proclivity to form beads. METHODS: We present data on 49 children with mercury intoxication (MI) and 60 children with mercury exposure from Turkey. RESULTS: The most common source of mercury was broken thermometer in schools. Inhaling mercury vapor was the most common route of exposure. The median exposure time was 6 (6-16) hours in the MI group, and the time to 1st symptoms was 10 (0-24) hours. In the MI group, the median blood mercury level was 21 µg/L (13-32.3), the median spot urine mercury level was 40 µg/L (7.66-78), and the median 24-hour urine mercury level was 25.8 µg/L (11-64). The most common symptoms in patients with MI were malaise, muscle pain, muscle cramps, abdominal pain, nausea, headache, and decreased appetite. The patients were treated with n-acetyl cysteine, 2,3-dimercaptopropane sulfonic acid, D-penicillamine, and meso 2,3-dimercaptosuccinic acid. A positive correlation was found between exposure time and urinary mercury level in the MI group (r = 0.793, P < 0.001). A positive moderate correlation was found between exposure time and blood level in the mercury exposure group (r = 0.535, P < 0.00). The neurological and systemic examinations of patients were all normal at the 1st follow-up visit 1 month after discharge. CONCLUSIONS: Diagnosis, removal of the exposure source, and use of chelation therapy can result in complete resolution of the signs and symptoms of MI.

Mercury Poisoning Presenting With Hypertension: Report of 2 Cases.

BACKGROUND: Mercury poisoning can cause damage to multiple organs. Secondary hypertension, which is usually misdiagnosed and mistreated, has been rarely reported in cases of mercury poisoning. METHODS: We herein present 2 cases of hypertension as the main manifestation of mercury poisoning. RESULTS: Case 1 involved a 42-year-old man with blood pressure of 230/190 mm Hg and urinary mercury level of 131.54 µmol/molCr. The patient had been repeatedly exposed to mercury at his workplace and had been admitted to our department many times. His hypertension quickly normalized after every chelation treatment. Case 2 involved a 10-year-old girl with hypertension (150/110 mm Hg), rash, and convulsions. She was found to have elevated blood levels of renin, angiotensin II, and aldosterone as well as an elevated urinary mercury level. Her hypertension recovered soon after chelation treatment. CONCLUSIONS: Mercury poisoning can cause secondary hypertension as the main clinical manifestation or together with multiorgan damage. Renin-angiotensin system activation may be involved in the occurrence and development of hypertension.

A Case of Accidental Mercury Intoxication.

BACKGROUND: Mercury poisoning is an uncommon diagnosis in the United States, but it is a differential diagnosis that physicians should consider because it can lead to potentially fatal complications if untreated. Due to the nonspecific presentation of mercury poisoning, which includes symptoms such as fever, nausea, vomiting, and abdominal pain, misdiagnosis may occur unless a proper history is taken. CASE REPORT: In the present case, a white female patient was misdiagnosed repeatedly with a viral illness and sent home from the local hospital. The patient presented with a diffuse full-body rash, fever, myalgias, headache, peripheral neuropathy, oral paresthesias, and tender cervical posterior lymphadenopathy. After obtaining a thorough history, it was discovered that the patient and her family were exposed to mercury through a spill of elemental mercury in their home. Blood mercury levels in the patient were 170 ng/mL. The patient was treated with a course of dimercaprol. Her symptoms improved and she was discharged on hospital day 5. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Ultimately, mercury poisoning is a treatable condition, but if exposure continues and the patient is not treated, it may lead to complications such as severe pneumonitis, renal tubular necrosis, and neurological dysfunction. In some instances, neurological symptoms may persist even if the source of exposure is removed. For these reasons, recognition and prompt treatment after a suspected exposure is important.

A Case of Mercury Toxicity Complicated by Acute Inflammatory Demyelinating Polyneuropathy.

A 13-year-old African American male presented with 2 months of subacute altered mental status, ptosis, areflexia, disordered gait, constipation, weight loss, abdominal and testicular pain, and hyperhidrosis. Initial workup at our facility was unrevealing until elevated serum mercury level was detected. Diagnosis of mercury toxicity was confirmed, and chelation therapy with succimer was started. After beginning succimer, the patient developed acute-onset weakness and was diagnosed with acute inflammatory demyelinating polyneuropathy. Supportive studies included elevated cerebrospinal fluid protein and acquired demyelinating polyneuropathy on nerve conduction study. He responded well to treatment with intravenous immunoglobulin and returned to his baseline state of health. Although there is a known association between mercury toxicity and axonal neuropathy, there is only 1 other case report of acute inflammatory demyelinating polyneuropathy in the setting of mercury toxicity. The nature of the correlation between these 2 entities in our case remains unclear.

Toxicidad asociada a vapores de mercurio en una lactante: a propósito de un caso / Mercury steam toxicity in a nursling: case report

La exposición a metales pesados como el mercurio genera toxicidad para los seres humanos, ocasionando riesgos neurológicos, respiratorios, hematológicos y renales, los cuales están directamente relacionados con el estado químico del metal, que está a su vez influenciado por la ruta de entrada al organismo, el tiempo de exposición, biotransformación y eliminación. Hay pocos informes de casos de toxicidad relacionada con vapores de mercurio, en los cuales hay compromiso neurológico y pulmonar. Presentamos el caso de una lactante expuesta de forma aguda a vapores de mercurio, quien presentó compromiso pulmonar como principal manifestación de toxicidad y respondió adecuadamente al tratamiento con Ácido Dimercapto Succínico (DMSA)

The exposition to heavy metals like mercury generates toxicity to humans, producing neurologic, pulmonary, hematologic and renal risks, which are directly related to the chemical state of the metal, also influenced by the route of access to the organism, time of exposition, biotransformation and elimination.There are few reports of toxicity related to mercury steam, with neurologic and pulmonary injury. Here we present the case of a nursling girl with acute exposition to mercury vapors, who presented with pulmonary injury as the main manifestation of toxicity, with a good recovery after Dimercapto Succinic Acid (DMSA) treatment

Mercury poisoning through intravenous administration: Two case reports with literature review.

RATIONALE: Metallic mercury poisoning through intravenous injection is rare, especially for a homicide attempt. Diagnosis and treatment of the disease are challenging. PATIENT CONCERNS: A 34-year-old male presented with pyrexia, chill, fatigue, body aches, and pain of the dorsal aspect of right foot. Another case is that of a 29-year-old male who committed suicide by injecting himself metallic mercury 15 g intravenously and presented with dizzy, dyspnea, fatigue, sweatiness, and waist soreness. DIAGNOSIS: The patient's condition in case 1 was deteriorated after initial treatment. Imaging studies revealed multiple high-density spots throughout the body especially in the lungs. On further questioning, the patient's girlfriend acknowledged that she injected him about 40 g mercury intravenously 11 days ago. The diagnosis was then confirmed with a urinary mercury concentration of 4828 mg/L. INTERVENTIONS: Surgical excision, continuous blood purification, plasma exchange, alveolar lavage, and chelation were performed successively in case 1. Blood irrigation and chelation therapy were performed in case 2. OUTCOMES: The laboratory test results and organ function of the patient in case 1 gradually returned to normal. However, in case 2, the patient's dyspnea was getting worse and he finally died due to toxic encephalopathy and respiratory failure. LESSONS: Early diagnosis and appropriate treatment are critical for intravenous mercury poisoning. It should be concerned about the combined use of chelation agents and other treatments, such as surgical excision, hemodialysis and plasma exchange in clinical settings.

A Mercury Toxicity Case Complicated by Hyponatremia and Abnormal Endocrinological Test Results.

Mercury (Hg) poisoning is considered a rare disease by the National Institutes of Health and the diagnosis can present great challenges to clinicians. Children who are exposed to Hg can present with a wide variety of symptoms, including acrodynia, tremor, excessive salivation, and psychiatric symptoms, including insomnia. However, endocrinologic manifestations from Hg exposure are less well known. This is a case report of a 12-year-old boy who presented with body rash, irritability, insomnia, and profuse sweating after returning from a summer camp. The child was initially managed in the outpatient setting, and the investigation was mainly targeted toward infectious etiology, including Rocky Mountain spotted fever and Lyme disease. He was eventually admitted to the hospital with altered mental status and was noted to have hyponatremia with serum sodium of 121 mEq/L. Thyroid studies also revealed elevated free thyroxine levels in the presence of normal triiodothyronine and thyrotropin. The patient developed hypertension and tachycardia, and was found to have elevated 24-hour vanillylmandelic acid and metanephrines. Finally, heavy metal measurements revealed a blood Hg level that was greater than the reference values of 0 to 9 ng/mL. Chelation treatment with 2,3-dimercaptopropane-1-sulfonate was subsequently initiated and over a period of 8 months his symptoms resolved and his thyroid function test returned to normal. This case highlights some of the challenges commonly encountered in identifying Hg exposure. More importantly, it illustrates that exposure to Hg should be considered in children who present with the symptoms and abnormal endocrinologic test results described in this report.

[Accidental mercury poisoning in a 12-year-old girl]. / Intoxication accidentelle au mercure chez l'enfant.

INTRODUCTION: Exposure to metallic mercury can cause severe accidental intoxications in children, whose clinical symptoms can vary depending on the route of administration, the dose, as well as the time and duration of the exposure. It has become unusual in France, yet it must be considered when taking a patient's medical history in cases of multisystemic involvement without a clear explanation. CLINICAL CASE: We report the case of a 12-year-old patient hospitalized because of a cough, poor general condition, chills, night sweats, psychomotor retardation, and skin lesions that had been developing for several weeks. The initial clinical examination also revealed sinus tachycardia, arterial hypertension, and abolition of osteotendinous reflexes. Complementary examination results were normal apart from a glomerular proteinuria without renal failure. When interviewing the mother, she reported that the child had played with mercury balls 3 months earlier. The suspicion of poisoning was confirmed by blood and urine analysis as well as renal biopsy showing an aspect of membranous glomerulonephritis with IgG and C3 depositions. An intoxication via a transdermal route being unlikely on healthy skin, the Regional Health Agency's survey concluded that chronic intoxication had occurred by inhalation of the mercury spread on the floor at the time of the exposure, which was then vacuum cleaned and released again by the contaminated vacuum cleaner. The patient's outcome was favorable within a few weeks after initiating DMSA chelation therapy. CONCLUSION: Mercury poisoning should be considered in cases of a multisystemic disorder without clear explanation, in order to intervene quickly and thus prevent irreversible renal and neurological consequences.

Mercury poisoning as a cause of intracranial hypertension.

Mercury poisoning is a rare but fatal toxicologic emergency. Neurologic manifestations involving the central nervous system are seen usually with chronic mercury intoxication. The most commonly seen complaints are headache, tremor, impaired cognitive skills, weakness, muscle atrophy, and paresthesia. Here, we present a male patient who was chronically exposed to elemental mercury and had papilledema and intracranial hypertension without parenchymal lesion in the central nervous system. A 12-year-old male patient was referred to our emergency room because of severe fatigue, generalized muscle pain and weakness, which was present for a month. Physical examination revealed painful extremities, decreased motor strength and the lack of deep tendon reflexes in lower extremities. He had mixed type polyneuropathy in his electromyography. Whole blood and 24-hour urinary mercury concentrations were high. A chelation therapy with succimer (dimercaptosuccinic acid) was started on the fourth day of his admission. On the seventh day of his admission, he developed headache and nausea, and bilateral papilledema and intracranial hypertension were detected on physical examination. Acetazolamide was started and after 1 month of treatment, the fundi examination was normal. The patient stayed in the hospital for 35 days and was then discharged with acetazolamide, vitamin B6, gabapentin, and followed as an outpatient. His clinical findings were relieving day by day. Although headache is the most common symptom in mercury poisoning, the clinician should evaluate the fundus in terms of intracranial hypertension.

Acute mercury poisoning presenting as fever of unknown origin in an adult woman: a case report.

INTRODUCTION: Mercury intoxication may present in a wide range of clinical forms from a simple disease to fatal poisoning. This article presents a case of acute mercury poisoning, a rare condition that presents challenges for diagnosis with fever of unknown origin. CASE PRESENTATION: A 52-year-old Caucasian woman was admitted to the hospital with high fever, sore throat, a rash over her entire body, itching, nausea, and extensive muscle pain. She had cervical, bilateral axillary and mediastinal lymphadenopathies. We learned that her son and husband had similar symptoms. After excluding infectious pathologies, autoimmune diseases and malignancy were investigated. Multiple organs of our patient were involved and her fever persisted at the fourth week of admission. A repeat medical history elicited that her son had brought mercury home from school and put it on the hot stove, and the family had been exposed to the fumes for a long period of time. Our patient's serum and urine mercury levels were high. She was diagnosed with mercury poisoning and treated accordingly. CONCLUSIONS: Mercury vapor is a colourless and odorless substance. Therefore, patients with various unexplained symptoms and clinical conditions should be questioned about possible exposure to mercury.

Notes from the field: elemental mercury spill in school bus and residence - North Carolina, 2013.

On September 16, 2013, the North Carolina Division of Public Health was notified of an elemental (metallic and liquid) mercury spill on a school bus. An elementary student boarded the bus with approximately 1 pound (454 g) of elemental mercury contained in a film canister, which the student had taken from an adult relative who had found it in a neighbor's shed. The canister was handled by several students before the contents spilled on the bus floor. Ten passengers aboard the bus were exposed, including eight students and two staff members. Although elemental mercury is not readily absorbed from skin contact or ingestion, it does vaporize at room temperatures and inhalation of the vapor can be harmful. The bus driver promptly notified school officials. Firefighters and a local hazardous materials team directed decontamination procedures (i.e., changing clothes and washing hands and shoes) for the 10 exposed passengers. The bus was immediately taken out of service and sent for disposal because of its age and the cost of decontamination.

Public health department response to mercury poisoning: the importance of biomarkers and risks and benefits analysis for chelation therapy.

Chelation therapy is often used to treat mercury poisoning. Public health personnel are often asked about mercury toxicity and its treatment. This paper provides a public health department response to use of a mercury-containing cosmetic in Minnesota, a perspective on two unpublished cases of chelation treatment for postulated mercury toxicity, and comments on the use of a nonsystemic treatment for removal of mercury following the Iraqi seed coat poisoning incident. Physicians should evaluate sources of exposure, biomarkers, and risks and benefits before recommending chelation therapy for their patients. Potential risks to chelation therapy and its little understood subtle or latent effects are areas of public health concern.

The role of chelation in the treatment of arsenic and mercury poisoning.

Chelation for heavy metal intoxication began more than 70 years ago with the development of British anti-lewisite (BAL; dimercaprol) in wartime Britain as a potential antidote the arsenical warfare agent lewisite (dichloro[2-chlorovinyl]arsine). DMPS (unithiol) and DMSA (succimer), dithiol water-soluble analogs of BAL, were developed in the Soviet Union and China in the late 1950s. These three agents have remained the mainstay of chelation treatment of arsenic and mercury intoxication for more than half a century. Animal experiments and in some instances human data indicate that the dithiol chelators enhance arsenic and mercury excretion. Controlled animal experiments support a therapeutic role for these chelators in the prompt treatment of acute poisoning by arsenic and inorganic mercury salts. Treatment should be initiated as rapidly as possible (within minutes to a few hours), as efficacy declines or disappears as the time interval between metal exposure and onset of chelation increases. DMPS and DMSA, which have a higher therapeutic index than BAL and do not redistribute arsenic or mercury to the brain, offer advantages in clinical practice. Although chelation following chronic exposure to inorganic arsenic and inorganic mercury may accelerate metal excretion and diminish metal burden in some organs, potential therapeutic efficacy in terms of decreased morbidity and mortality is largely unestablished in cases of chronic metal intoxication.

Medical toxicology case presentations: to chelate or not to chelate, is that the question?

Four case studies described in this article were presented to a panel of physicians participating in the ACMT "Use and Misuse of Metal Chelation Therapy" Symposium in February 2012. The individuals who participated in the panel are listed in the appendix. These cases highlight some of the practical questions facing medical providers when issues of metal toxicity and its treatment arise. Medical toxicologists are valuable resources for information, public debate, consultation, and treatment of patients with concerns about heavy metal exposure.