Heavy Metal Poisoning — MCQs
Buon's line is seen in: Al 07; Rajasthan 11; NEET 13; JIPMER 13
Pink disease is seen in
Which poison is most likely to cause megaloblastic anemia?
A patient presents with complaints of hair loss and behavioral changes noted by his wife. Upon examination, the doctor observes a loss of eyebrows. After further assessment, including an examination of the nails, what type of poisoning is suspected in this case?
A 35-year-old construction worker presents with a 3-month history of abdominal pain, fatigue, and recent onset of numbness and tingling in his hands and feet. He works in renovation of old buildings. Physical examination reveals mild pallor and decreased sensation in a stocking-glove distribution. Blood tests show microcytic anemia with basophilic stippling on peripheral smear. What is the most likely diagnosis?
An industrial worker presents with blue lines on gums and tremors. What is the most probable diagnosis?
Which of the following poisonings presents with abdominal pain, diarrhea, Mees lines on nails, and myelosuppression?
Which of the following substances is a toxin but has also been historically used as a therapeutic emetic in poisoning management?
Acrodynia, or Pink disease, occurs in poisoning with which of the following substances?
The most common toxin causing dilated cardiomyopathy is
Heavy Metal Poisoning Indian Medical PG Practice Questions and MCQs
Question 1: Buon's line is seen in: Al 07; Rajasthan 11; NEET 13; JIPMER 13
- A. Phosphorus poisoning
- B. Zinc poisoning
- C. Lead poisoning (Correct Answer)
- D. Arsenic poisoning
Explanation: ***Lead poisoning*** - **Buon's line**, also known as a **gingival lead line** or **Burton's line**, is a blue-black line visible on the gums at the junction of the teeth, characteristic of chronic lead poisoning. - This line is formed by the reaction of circulating lead with sulfur ions released by bacterial action in the mouth, forming **lead sulfide** deposits. *Phosphorus poisoning* - **Phosphorus poisoning** can cause widespread organ damage, including gastrointestinal symptoms, liver and kidney failure, and cardiovascular collapse. - It does not typically present with a characteristic gingival line like Buon's line. *Zinc poisoning* - **Zinc poisoning** is relatively rare and can lead to symptoms like nausea, vomiting, abdominal pain, and copper deficiency. - It is not associated with the formation of Buon's line in the gums. *Arsenic poisoning* - **Arsenic poisoning**, particularly chronic exposure, can manifest with skin lesions, neuropathies, and gastrointestinal issues. - A characteristic skin manifestation is **Mee's lines** (transverse white bands on the fingernails), but not Buon's line.
Question 2: Pink disease is seen in
- A. Lead poisoning
- B. Cyanide poisoning
- C. Carbon monoxide poisoning
- D. Mercury poisoning (Correct Answer)
Explanation: ***Mercury poisoning*** - Pink disease, also known as **Acrodynia**, is a rare but severe manifestation of **chronic mercury poisoning** in infants and young children [2]. - Clinical features include a **pinkish-red rash** on the hands and feet, generalized erythema, irritability, photophobia, and hypotonia. *Lead poisoning* - Lead poisoning primarily affects the **nervous system**, **hematologic system**, and **kidneys** [1]. - Symptoms include abdominal pain, constipation, developmental delay, and a **lead line** on the gums, but not a characteristic pink rash [1]. *Cyanide poisoning* - Cyanide poisoning is an acute and rapidly progressing condition that interferes with **cellular respiration**, leading to hypoxia. - Typical signs include headache, dizziness, rapid breathing, and a **bright red flushing** of the skin, not pink disease. *Carbon monoxide poisoning* - Carbon monoxide poisoning occurs when CO binds to hemoglobin, forming **carboxyhemoglobin** and reducing oxygen transport. - Victims often present with a **cherry-red appearance** of the skin and mucous membranes due to carboxyhemoglobin, distinct from the pink rash of acrodynia.
Question 3: Which poison is most likely to cause megaloblastic anemia?
- A. Copper
- B. Lead
- C. Mercury
- D. Arsenic (Correct Answer)
Explanation: ***Arsenic*** - **Arsenic poisoning** can cause various hematological abnormalities, and in chronic exposure, it may interfere with **folate metabolism** and **DNA synthesis**, potentially leading to **megaloblastic anemia**. - While **aplastic anemia** and **hemolytic anemia** are more commonly associated with arsenic toxicity, megaloblastic changes can occur due to disruption of normal erythrocyte maturation. - Among the given options, arsenic has the strongest association with megaloblastic anemia, though this is **not the most common hematological manifestation** of arsenic poisoning. *Copper* - **Copper deficiency** causes **microcytic hypochromic anemia** (similar to iron deficiency) due to impaired iron metabolism. - **Copper toxicity** (Wilson's disease) may cause **hemolytic anemia** but not megaloblastic anemia. *Lead* - **Lead poisoning** characteristically causes **sideroblastic anemia** with **basophilic stippling** of RBCs. - Lead inhibits enzymes in heme synthesis pathway, leading to accumulation of iron in mitochondria. - Does **not** cause the macrocytic changes seen in megaloblastic anemia. *Mercury* - **Mercury poisoning** primarily causes **neurotoxicity** (tremors, cognitive impairment, ataxia) and **nephrotoxicity**. - Not associated with megaloblastic anemia; any anemia is typically secondary to chronic disease or renal dysfunction.
Question 4: A patient presents with complaints of hair loss and behavioral changes noted by his wife. Upon examination, the doctor observes a loss of eyebrows. After further assessment, including an examination of the nails, what type of poisoning is suspected in this case?
- A. Thallium (Correct Answer)
- B. Arsenic
- C. Mercury
- D. Lead
Explanation: ***Thallium*** - **Thallium poisoning** characteristically presents with **hair loss (alopecia)**, including loss of eyebrows, and **neurological symptoms** such as behavioral changes. - It also causes nail changes like **Mees' lines** and is known for its **neurotoxic effects**. *Arsenic* - **Arsenic poisoning** primarily causes **gastrointestinal symptoms** (nausea, vomiting, diarrhea), **skin lesions** (hyperpigmentation, hyperkeratosis), and **neuropathy**. - While it can cause nail changes (Mees' lines), significant alopecia and loss of eyebrows are less prominent compared to thallium. *Mercury* - **Mercury poisoning** often leads to **neurological symptoms** (tremors, ataxia, irritability), kidney damage, and **gingivostomatitis**. - Hair loss and loss of eyebrows are not typical or prominent features of mercury toxicity. *Lead* - **Lead poisoning** is associated with **neurodevelopmental deficits** in children, **peripheral neuropathy**, **abdominal pain (lead colic)**, and **anemia**. - Alopecia and loss of eyebrows are not characteristic symptoms of lead toxicity.
Question 5: A 35-year-old construction worker presents with a 3-month history of abdominal pain, fatigue, and recent onset of numbness and tingling in his hands and feet. He works in renovation of old buildings. Physical examination reveals mild pallor and decreased sensation in a stocking-glove distribution. Blood tests show microcytic anemia with basophilic stippling on peripheral smear. What is the most likely diagnosis?
- A. Coeliac disease
- B. Sickle cell disease
- C. Lead poisoning (Correct Answer)
- D. Hookworm infestation
Explanation: **Lead poisoning** - The patient's occupation in **renovating old buildings** poses a significant risk for lead exposure [1]. - Classic symptoms of lead poisoning, such as **abdominal pain** [1], **fatigue**, **peripheral neuropathy** (numbness/tingling in stocking-glove distribution) [2], **pallor** [2], **microcytic anemia**, and **basophilic stippling** [1], are all present. *Coeliac disease* - While it can cause **abdominal pain** and **fatigue** due to malabsorption, it typically leads to **iron deficiency anemia**. - **Neuropathy** is less common and **basophilic stippling** is not a feature of coeliac disease. *Sickle cell disease* - Causes **hemolytic anemia** and painful crises, but is a genetic disorder typically diagnosed in childhood and presents with different symptoms. - While it can present with **fatigue** and **pallor**, **basophilic stippling** is not typical, and neuropathy in a stocking-glove distribution is rare. *Hookworm infestation* - Primarily causes **iron deficiency anemia** due to chronic blood loss from the gut, leading to **fatigue** and **pallor**. - It does not typically cause **basophilic stippling** or prominent **peripheral neuropathy** as described.
Question 6: An industrial worker presents with blue lines on gums and tremors. What is the most probable diagnosis?
- A. Mercury
- B. Lead (Correct Answer)
- C. Arsenic poisoning
- D. Carbon monoxide
Explanation: ***Lead*** - **Blue lines on the gums (Burton's lines)** are a classic symptom of chronic lead poisoning, caused by a reaction between circulating lead and sulfur ions released by oral bacteria [2]. - **Tremors** and other neurological symptoms like *wrist drop* or *foot drop* are common manifestations of lead's neurotoxic effects [1]. *Mercury* - While **tremors** are a prominent symptom of mercury poisoning, especially *finger tremors* and *erectile dysfunction*, **blue lines on the gums** are not characteristic [3]. - Mercury poisoning is often associated with **gingivitis**, **stomatitis**, and *Erythrism* (mad hatter disease), which involves psychological changes like irritability and shyness [3]. *Arsenic poisoning* - **Arsenic poisoning** can cause **neuropathy**, but **tremors** and **blue lines on the gums** are not typical features. - It classically presents with **rain drop skin pigmentation**, **hyperkeratosis**, and **Mees' lines** (transverse white bands on nails). *Carbon monoxide* - **Carbon monoxide poisoning** primarily affects the cardiovascular and central nervous systems, leading to symptoms like **headache**, **nausea**, and cherry-red skin coloration. - **Blue lines on the gums** and **tremors** are not associated with carbon monoxide toxicity.
Question 7: Which of the following poisonings presents with abdominal pain, diarrhea, Mees lines on nails, and myelosuppression?
- A. Lead
- B. Arsenic (Correct Answer)
- C. Alcohol
- D. Mercury
Explanation: ***Arsenic*** - **Arsenic poisoning** is characterized by gastrointestinal symptoms like severe **abdominal pain** and **diarrhea**, as well as dermatological signs such as **Mees lines** (transverse white bands on fingernails). - It also causes **myelosuppression**, leading to anemia, leukopenia, and thrombocytopenia, and can affect the cardiovascular and nervous systems. *Lead* - **Lead poisoning** typically presents with diffuse **abdominal pain** (lead colic), **constipation** (not diarrhea), and neurological symptoms like **foot drop** and **encephalopathy**. - While it can cause anemia due to impaired heme synthesis, **Mees lines** and significant myelosuppression are not primary features. *Alcohol* - **Alcohol intoxication** or chronic alcoholism primarily affects the central nervous system, liver, and pancreas, leading to symptoms like **ataxia**, **hepatitis**, and **pancreatitis**. - It does not cause **Mees lines** or the specific combination of severe gastrointestinal issues and myelosuppression seen with arsenic. *Mercury* - **Mercury poisoning** typically manifests with neurological symptoms (tremors, emotional lability, **peripheral neuropathy**), stomatitis, and renal dysfunction. - While it can cause gastrointestinal upset, **Mees lines** and **myelosuppression** are not characteristic features of mercury toxicity.
Question 8: Which of the following substances is a toxin but has also been historically used as a therapeutic emetic in poisoning management?
- A. Thallium
- B. Copper sulphate (Correct Answer)
- C. Arsenic oxide
- D. Mercuric chloride
Explanation: ***Copper sulphate*** - **Copper sulphate** is a **potent toxin** that causes gastrointestinal irritation, hemolysis, hepatotoxicity, and acute renal failure upon ingestion. - It was **historically used as an emetic** to induce vomiting in certain poisoning cases for gastric decontamination, though this practice has been largely abandoned due to its own significant toxicity and the availability of safer alternatives. - This represents its dual nature: a poison itself, yet paradoxically used in poisoning management (not as an antidote, but as a gastric evacuant). *Thallium* - **Thallium** is a highly toxic heavy metal causing severe multi-organ failure, alopecia, peripheral neuropathy, and potentially fatal systemic toxicity. - It has **no therapeutic use** in poisoning management and is purely a toxicological concern. *Arsenic oxide* - **Arsenic oxide** (arsenic trioxide) is a well-known carcinogen and potent cellular poison that disrupts oxidative phosphorylation. - While it has modern therapeutic use in acute promyelocytic leukemia, it has **never been used in poisoning management** as an emetic or therapeutic agent. *Mercuric chloride* - **Mercuric chloride** is highly corrosive and causes severe gastrointestinal burns, acute tubular necrosis, and systemic mercury toxicity. - It is a **potent toxin with no therapeutic application** in poisoning management.
Question 9: Acrodynia, or Pink disease, occurs in poisoning with which of the following substances?
- A. Lead
- B. Thallium
- C. Arsenic
- D. Mercury (Correct Answer)
Explanation: ***Mercury*** - **Acrodynia**, also known as **Pink disease**, is a rare and severe form of **mercury poisoning**, primarily affecting infants and young children. - Key symptoms include **pinkish-red rash** on the hands and feet, hypertension, irritability, profuse sweating, and muscle weakness. *Lead* - **Lead poisoning** typically presents with symptoms such as **abdominal pain**, constipation, developmental delay, and a **lead line on the gums**. - It does not cause the characteristic rash or other symptoms associated with acrodynia. *Thallium* - **Thallium poisoning** is known for causing **hair loss (alopecia)**, excruciating neuropathic pain, gastrointestinal disturbances, and neurological symptoms. - While it is a neurotoxic heavy metal, its clinical picture is distinct from acrodynia. *Arsenic* - **Arsenic poisoning** can manifest with dermatological signs like **hyperpigmentation** and **hyperkeratosis**, as well as gastrointestinal and neurological symptoms. - It does not produce the pinkish rash, irritability, or hypertension typical of acrodynia.
Question 10: The most common toxin causing dilated cardiomyopathy is
- A. Industrial solvents
- B. Alcohol (Correct Answer)
- C. Chemotherapeutic agents
- D. Heavy metal
Explanation: ***Alcohol*** - Chronic excessive **alcohol consumption** is the most common toxic cause of dilated cardiomyopathy [1]. - Alcohol and its metabolite **acetaldehyde** directly damage myocardial cells, leading to impaired contractility and ventricular dilatation [1]. *Industrial solvents* - Exposure to certain industrial solvents, such as **toluene** or **trichloroethylene**, has been linked to cardiotoxicity and arrhythmias, but they are not the most common cause of dilated cardiomyopathy. - The cardiotoxic effects are less prevalent and typically associated with specific occupational exposures rather than widespread consumption. *Chemotherapeutic agents* - Certain **chemotherapeutic agents**, particularly **anthracyclines** (e.g., doxorubicin), are known to cause dilated cardiomyopathy as a significant side effect. - However, while important, this is an iatrogenic cause and not as common as chronic alcohol use in the general population. *Heavy metal* - Exposure to **heavy metals** such as cobalt, lead, or mercury can cause cardiotoxicity and contribute to cardiomyopathy. - These are typically rarer causes, often linked to environmental or occupational exposure, and do not represent the most common toxic etiology.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free