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| ==Background==
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| Heavy metal toxicity results from exposure to metals like lead, mercury, arsenic, or cadmium, which interfere with cellular function. Exposure may occur occupationally, environmentally, through ingestion, or from alternative medicines. Chronic toxicity can present insidiously, while acute toxicity may mimic sepsis or encephalopathy. Diagnosis is often delayed due to nonspecific symptoms.
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| ==Clinical Features==
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| Symptoms depend on the metal and exposure duration but may include:
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| Neurologic: Peripheral neuropathy, confusion, tremor, encephalopathy
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| GI: Abdominal pain, nausea, vomiting, diarrhea, anorexia
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| Heme: Anemia (especially microcytic or hemolytic), basophilic stippling (lead)
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| Renal: Tubular dysfunction, proteinuria, Fanconi syndrome
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| Dermatologic: Mees’ lines (arsenic), hyperpigmentation, hair loss
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| Others: Fatigue, weight loss, hypertension (cadmium), immunosuppression
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| ==Differential Diagnosis==
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| [[Sepsis (main)|Sepsis]] or systemic inflammatory response
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| Drug toxicity or overdose
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| Metabolic disorders (e.g., [[Porphyria|porphyria]], [[Uremia|uremia]])
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| Psychiatric illness (if symptoms are vague or bizarre)
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| Neurologic diseases (e.g., [[Guillain-Barre syndrome|Guillain-Barré]], [[Multiple sclerosis|MS]], [[Parkinson's disease|Parkinson’s]])
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| [[Vitamin deficiencies]] (e.g., B12, thiamine)
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| ==Evaluation==
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| ===Workup===
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| History: Occupational exposures, home remedies, hobbies (e.g., jewelry making, battery recycling), diet, water source, imported goods
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| Labs:
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| * CBC, CMP, urinalysis
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| * Blood lead level, serum/urine arsenic, mercury, or cadmium (based on suspicion)
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| * Urine heavy metal screen (note: spot testing may require creatinine correction)
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| Imaging: Abdominal X-ray (radiopaque material in GI tract, especially with lead)
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| EKG: Evaluate for QT prolongation or arrhythmias in severe cases
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| ===Diagnosis===
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| Confirmed by elevated blood or urine levels of the specific metal in the context of clinical findings. Hair and nail testing are unreliable for acute toxicity. Interpret results with toxicologist input if possible.
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| ==Management==
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| Remove the source of exposure (e.g., occupational control, GI decontamination if recent ingestion)
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| Supportive care: IV fluids, seizure control, electrolyte repletion
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| Chelation therapy (in consultation with toxicology or Poison Control):
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| Lead: EDTA, dimercaprol (BAL), succimer
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| Mercury/arsenic: Dimercaprol or DMSA
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| Cadmium: No effective chelation—focus on supportive care
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| Notify local public health authorities if exposure source is environmental or occupational
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| ==Disposition==
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| Admit if symptomatic, unstable, or requiring chelation
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| Discharge may be appropriate for asymptomatic patients with low-level exposure and outpatient follow-up
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| Arrange toxicology or environmental medicine follow-up for source control and serial testing
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| ==See Also== | | ==See Also== |
