What are the symptoms and treatment of lead poisoning?

Lead Poisoning Symptoms and Treatment

Lead poisoning requires immediate identification of the source and removal from exposure, followed by chelation therapy for blood lead levels ≥45 μg/dL or for symptomatic patients. 1

Symptoms of Lead Poisoning

Lead toxicity affects multiple body systems with varying symptoms based on exposure level and duration:

Neurological Symptoms

• Children:

  • Cognitive dysfunction and decreased IQ
  • Developmental delays
  • Behavioral changes including hyperactivity and irritability 1, 2
  • Seizures and encephalopathy (at high levels) 1, 3
  • Speech problems including aphasia (in severe cases) 3

• Adults:

  • Memory problems
  • Concentration difficulties
  • Irritability
  • Headaches 1

Gastrointestinal Symptoms

• Abdominal pain (can be severe and mimic acute abdomen) 1, 4
• Poor appetite
• Constipation or diarrhea 2
• Nausea and vomiting 4

Hematological Effects

• Microcytic, hypochromic anemia (hemoglobin typically 8-10 g/dL) 1, 2
• Decreased mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) 2
• Basophilic stippling of red blood cells 4

Other Systems

• Renal: Nephrotoxicity that can progress to chronic renal failure 1
• Cardiovascular: Increased blood pressure 1
• Musculoskeletal: Weakness of extremities, wrist drop (in severe cases) 4

Diagnostic Approach

• Blood lead level (BLL) testing is the standard diagnostic approach 1

• BLL interpretation:

  Blood Lead Level (μg/dL)	Interpretation
  <5	No safe level exists, monitor and identify sources
  5-14	Environmental investigation needed
  15-44	Requires confirmation within 1-4 weeks
  >44	Urgent confirmation within 48 hours, consider chelation

• Additional tests:

  • Complete blood count to assess for anemia
  • Serum creatinine to identify renal dysfunction
  • X-rays may show "lead lines" in long bones 4

Treatment Approach

1. Source Identification and Removal

• Primary intervention: Complete removal from the source of exposure 1
• Common sources include:
  • Lead-based paint in homes built before 1978
  • Contaminated drinking water
  • Folk remedies and traditional medicines 1, 3
  • Occupational exposure
  • Contaminated soil
  • Imported toys, jewelry, pottery, and cosmetics 1

2. Supportive Nutritional Measures

• Regular meals with adequate:
  • Iron (especially with concurrent iron deficiency)
  • Calcium (decreases bone resorption and minimizes lead release)
  • Vitamin C 1

3. Chelation Therapy

• Indications:

  • BLLs ≥45 μg/dL in children
  • BLLs ≥100 μg/dL in adults (always warranted)
  • BLLs 80-99 μg/dL in adults (regardless of symptoms)
  • BLLs 50-79 μg/dL in adults with symptoms 1

• Chelating agents:

  • Succimer (DMSA) - oral agent, often first-line for children
  • Calcium Disodium EDTA - intravenous
  • Dimercaprol (BAL) - for severe cases 1, 2

• Important considerations:

  • Consult with medical toxicologist or occupational medicine specialist
  • Monitor urinary lead excretion, BLL, liver function, renal function, and complete blood count
  • Maintain patient in lead-safe environment during chelation
  • Repeated courses may be necessary with treatment-free periods between courses 1

Monitoring and Follow-up

• Follow-up BLL testing schedule:
  • BLLs <10 μg/dL: Semiannual testing
  • BLLs 10-19 μg/dL: Quarterly testing
  • BLLs 20-29 μg/dL: Monthly testing until levels decline 1

Prevention

• Environmental remediation of lead sources
• Regular education about lead hazards
• Running water until cold before using for cooking or drinking
• Screening high-risk children at 12 and 24 months of age 1, 5

Clinical Pitfalls to Avoid

1. Missed diagnosis: Lead poisoning often presents with nonspecific symptoms that can be mistaken for other conditions 6, 4

   • Abdominal pain may be mistaken for acute abdomen, leading to unnecessary surgeries 4
   • Behavioral changes may be attributed to developmental or psychiatric disorders

2. Inadequate source identification: Failure to identify and remove the source of lead exposure will result in continued toxicity despite treatment 1

3. Delayed treatment: Neurological damage from lead exposure can be irreversible, particularly in children 1, 3

4. Overlooking at-risk populations: Children under 5 years, pregnant women, and those from low socioeconomic backgrounds are at higher risk 5

5. Incomplete follow-up: Patients require ongoing monitoring after initial treatment to ensure BLLs continue to decrease 1