Lead Poisoning (Plumbism)

Key Features

• Usually occurs insidiously in children younger than age 5 years

• Most likely sources include

  • Flaking leaded paint

  • Artist's paints

  • Fruit tree sprays

  • Solder

  • Brass alloys

  • Home-glazed pottery

  • Fumes from burning batteries

  • Foreign country remedies

• Only paint containing < 1% lead is safe for interior use (eg, furniture, toys)

• Repetitive ingestions of small amounts of lead are far more serious than a single massive exposure

• Toxic effects are likely to occur if more than 0.5 mg of lead per day is absorbed

• In the United States, lead levels continue to decline and are more common abroad, so particular attention should be paid to immigrant and refugee populations or use of foreign remedies

Clinical Findings

• Causes vague symptoms, including

  • Weakness

  • Irritability

  • Weight loss

  • Vomiting

  • Personality changes

  • Ataxia

  • Constipation

  • Headache

  • Colicky abdominal pain

• Late manifestations consist of developmental delays, convulsions, and coma associated with increased intracranial pressure, which is a medical emergency

Diagnosis

• Blood lead levels are used to assess the severity of exposure

• A complete blood cell count and serum ferritin concentration should be obtained; iron deficiency increases absorption of lead

• Glycosuria, proteinuria, hematuria, and aminoaciduria occur frequently

• A normocytic, slightly hypochromic anemia with basophilic stippling of the red cells and reticulocytosis may be present

• Lumbar punctures

  • Must be performed cautiously to prevent herniation

  • Cerebrospinal fluid (CSF) protein is elevated, and the white cell count usually is < 100 cells/mL

  • CSF pressure may be elevated in patients with encephalopathy

Treatment

• Refer to the CDC guidelines for the most up to date recommendations on lead treatment

• Removing the source of exposure is the most important initial treatment to toxicity

• Succimer

  • Approved for use in children and reported to be as efficacious as calcium edetate

  • Should be initiated in asymptomatic children who have blood lead levels over 45 μg/dL

  • Initial dose is 10 mg/kg (350 mg/m²) every 8 hours for 5 days.

  • Same dose is then given every 12 hours for 14 days

  • At least 2 weeks should elapse between courses

  • Blood lead levels increase somewhat (ie, rebound) after discontinuation of therapy

• Courses of dimercaprol/BAL (300–450 mg/m²/d) and calcium sodium edetate/CaNa2EDTA (1000–1500 mg/m²/d) should be considered in symptomatic children or levels over 70 μg/dL

• Encephalopathy associated with cerebral edema needs to be treated with standard measures; anticonvulsants may be needed

• A high-calcium, high-phosphorus diet and large doses of vitamin D may remove lead from the blood by depositing it in the bones