Symptoms and Treatment of Lead Poisoning
Lead poisoning requires prompt identification of symptoms and blood lead level-based treatment, with chelation therapy indicated for levels above 45 μg/dL in children and 70 μg/dL in adults with symptoms. 1, 2
Symptoms of Lead Poisoning
Lead poisoning affects multiple organ systems with varying symptoms depending on blood lead levels:
Neurological Symptoms
- Developmental delays and decreased intelligence in children 1
- Cognitive dysfunction in adults 1
- Irritability and behavioral changes 1
- Seizures and encephalopathy at high levels 3
- Progressive neurological deterioration including paraplegia and aphasia in severe cases 3
Gastrointestinal Symptoms
Hematological Symptoms
Other Symptoms
Diagnosis
- Blood lead level (BLL) is the primary diagnostic test 1
- Zinc protoporphyrin (ZPP) concentration reflects lead exposure over the prior 3 months 5
- Abdominal radiography should be considered for children with pica behavior 1
- Detailed environmental and occupational history is crucial 5
Treatment Protocol Based on Blood Lead Levels
Children
BLL <5 μg/dL (<50 ppb)
- Review results with family 1
- Provide anticipatory guidance about common lead exposure sources 1
- Assess nutrition and development 1
- Repeat testing in 6-12 months if high risk 1
BLL 5-14 μg/dL (50-140 ppb)
- Notify local health authorities 1
- Identify and eliminate lead sources 1
- Retest within 1-3 months 1
- Provide nutritional counseling (calcium and iron) 1
- Screen for iron deficiency and treat if present 1
- Monitor development closely 1
BLL 15-44 μg/dL (150-440 ppb)
- Confirm with repeat venous sample within 1-4 weeks 1
- Consider abdominal radiography for children with pica 1
- Consult with local pediatric environmental health specialty unit 1
- Continue nutritional interventions and monitoring 1
BLL >44 μg/dL (>440 ppb)
- Confirm with repeat venous sample within 48 hours 1
- Consider hospitalization 1
- Initiate chelation therapy with expert consultation 1, 2
- Edetate calcium disodium (EDTA) is recommended at 1,000 mg/m²/day for 5 days 2
- For severe cases with encephalopathy, combine with dimercaprol (BAL) 2, 5
Adults
BLL <5 μg/dL
- No specific action needed 1
BLL 5-9 μg/dL
BLL 10-19 μg/dL
- Discuss health risks and decrease exposure 1
- Monitor BLL quarterly 1
- Remove from exposure for pregnancy or certain medical conditions 1
BLL 20-29 μg/dL
- Remove from occupational exposure if repeat BLL in 4 weeks remains ≥20 μg/dL 1
BLL 30-79 μg/dL
BLL ≥80 μg/dL
Chelation Therapy
- Edetate calcium disodium (EDTA) is the primary chelating agent 2
- For asymptomatic patients with BLL <70 μg/dL but >20 μg/dL: 1,000 mg/m²/day for 5 days 2
- For patients with very high BLL (>70 μg/dL) or symptoms: combine EDTA with BAL (dimercaprol) 2
- For adults with lead nephropathy, reduced dosing based on creatinine levels 2
- Therapy is typically administered over 5 days, interrupted for 2-4 days, then repeated 2
- Monitor urine output during chelation as EDTA is excreted renally 2
- Avoid excessive fluid in patients with encephalopathy 2
Important Considerations and Pitfalls
- Lead poisoning can be easily misdiagnosed as other conditions like acute porphyria or nonspecific abdominal pain 4
- Blood lead levels may rebound after chelation due to redistribution from bone stores 6
- Chelation therapy alone is insufficient without identifying and removing the source of exposure 2
- Excessive doses of chelating agents can cause zinc deficiency and renal toxicity 2
- Pregnant women should avoid lead exposure that would result in BLL >5 μg/dL 1
- Children are particularly vulnerable to lead's neurodevelopmental effects, which may be irreversible 3