From the Guidelines
The workup for a 2-year-old with potential lead exposure should begin with a blood lead level (BLL) test, which is the primary screening method, as recommended by the American Academy of Pediatrics (AAP) 1. This should be performed using venous blood sampling, as capillary samples can be contaminated by environmental lead. A complete history should be obtained, focusing on potential sources of exposure such as:
- old housing with lead paint
- parental occupations involving lead
- imported toys or pottery
- folk remedies, as outlined in the AAP's guidance on prevention of childhood lead toxicity 1. A physical examination should assess for signs of lead toxicity, though many children are asymptomatic. For children with elevated BLLs (≥5 μg/dL), additional testing should include:
- complete blood count to check for anemia
- iron studies
- possibly abdominal X-rays if ingestion of lead objects is suspected, as recommended by the AAP 1. Children with BLLs ≥45 μg/dL require emergency evaluation and may need chelation therapy with medications such as succimer (DMSA), dimercaprol (BAL), or calcium disodium EDTA, depending on severity, as outlined in the AAP's guidance on prevention of childhood lead toxicity 1. Environmental investigation is crucial to identify and remove the source of exposure, and pediatricians should be familiar with collection and interpretation of reports of lead hazards found in house dust, soil, paint, and water, or refer families to a specialist who is familiar with these tools 1. Lead affects multiple body systems, particularly the developing nervous system, which is why early detection in young children is essential to prevent long-term neurodevelopmental consequences, as highlighted in the AAP's policy statement on prevention of childhood lead toxicity 1.
From the FDA Drug Label
Several methods have been described for lead mobilization tests using edetate calcium disodium to assess body stores. Elevated erythrocyte protoporphyrin levels (> 35 mcg/dl of whole blood) indicate the need to perform a venous blood lead determination. If the whole blood lead concentration is between 25 to 55 mcg/dl a mobilization test can be considered. Urinary coproporphyrin may be falsely negative in terminal patients and in severely iron-depleted pediatric patients who are not regenerating heme. In growing pediatric patients long bone x-rays showing lead lines and abdominal x-rays showing radio-opaque material in the abdomen may be of help in estimating the level of exposure to lead.
The workup for a 2-year-old with potential lead exposure includes:
- Venous blood lead determination if erythrocyte protoporphyrin levels are elevated (> 35 mcg/dl of whole blood)
- Mobilization test if whole blood lead concentration is between 25 to 55 mcg/dl
- Urinary coproporphyrin test
- Long bone x-rays to check for lead lines
- Abdominal x-rays to check for radio-opaque material in the abdomen 2, 2
From the Research
Workup for a 2-year-old with Potential Lead Exposure
The workup for a 2-year-old with potential lead exposure involves several steps, including:
- Obtaining an environmental history to identify potential sources of lead exposure 3
- Blood lead screening to determine the level of lead in the child's blood 3, 4
- Providing lead-prevention counseling to families to help them establish a lead-safe environment for their children 3
- Referral to developmental programs for children at high risk for exposure to lead 3
- More frequent rescreening of children with blood lead levels approaching 10 microg/dL 3
Laboratory Testing
Laboratory testing for lead exposure includes:
- Blood lead level testing to determine the level of lead in the child's blood 3, 5, 6, 7, 4
- Interpreting blood lead levels in the context of laboratory error range and selecting a laboratory that achieves routine performance within +/-2 microg/dL 3
Management and Treatment
Management and treatment of lead exposure in children includes:
- Identification and removal of sources of lead exposure 3, 6
- Chelation therapy for children with high blood lead levels, although the indications for chelation therapy have not changed 6
- Use of oral chelating agents such as succimer, which appears to have fewer side effects and is more effective than other chelating agents 5, 6