A 3-year-old boy is brought to the office for a routine visit. The patient is doing well, and his parents have no concerns. Review of systems is unremarkable. He was recently adopted from China; his medical and family history is unknown. The patient takes no daily medications and has received all recommended immunizations. His adoptive parents are schoolteachers, and the family lives in a newly built home. Vital signs are appropriate for age, and BMI is at the 40th percentile. Examination shows a quiet and alert boy. Cardiac, pulmonary, and abdominal examinations are unremarkable. Complete blood count and serum electrolytes are normal. Venous lead level is 60 µg/dL (normal:

Question

A 3-year-old boy is brought to the office for a routine visit.  The patient is doing well, and his parents have no concerns.  Review of systems is unremarkable.  He was recently adopted from China; his medical and family history is unknown.  The patient takes no daily medications and has received all recommended immunizations.  His adoptive parents are schoolteachers, and the family lives in a newly built home.  Vital signs are appropriate for age, and BMI is at the 40th percentile.  Examination shows a quiet and alert boy.  Cardiac, pulmonary, and abdominal examinations are unremarkable.  Complete blood count and serum electrolytes are normal.  Venous lead level is 60 µg/dL (normal: <5).  X-ray of the abdomen reveals no lead-containing foreign bodies.  Lead toxicity and exposure are discussed with the family.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c015_d7d4_8f63_b337a3aba193_MD0005_00 Infants and young children are particularly vulnerable to lead toxicity secondary to age-appropriate oral exploration. They can unintentionally ingest lead particles, leading to gradual, toxic accumulation of lead and long-term neurodevelopmental problems. Although paint in the United States has been lead-free since 1978, houses built before then continue to be a source of lead toxicity. All international adoptees and immigrants should also be screened routinely for lead levels due to possible lead exposure in their native country. Chelation therapy increases urinary lead excretion by binding lead in blood and should be administered to patients with levels >45 µg/dL to reduce the blood lead level. First-line treatment for moderate asymptomatic toxicity (45-69 µg/dL) is meso-2,3-dimercaptosuccinic acid (DMSA, succimer), which can be administered orally and has few side effects (eg, rash, neutropenia). (Choice A) Severe lead toxicity (≥70 μg/dL and/or acute encephalopathy) is a medical emergency requiring hospitalization for chelation. Severe toxicity should be treated with intramuscular dimercaprol, which can cross the blood-brain barrier, followed by intravenous calcium disodium edetate (EDTA) to decrease the risk or severity of encephalopathy. Succimer alone is sufficient for asymptomatic, moderate lead toxicity. (Choice B) Repeating a lead level in 1 month is appropriate management for mildly elevated lead levels (ie, 5-44 μg/dL). Delaying therapy in this patient would be inappropriate and increase the likelihood of neurodevelopmental problems. (Choice C) Activated charcoal is indicated for gastric decontamination after acute life-threatening medication ingestions (eg, carbamazepine, phenobarbital) and works best if given within an hour of lead ingestion. Lead ingestion is typically chronic. (Choice D) Oral D-penicillamine is the primary chelating treatment for copper removal in Wilson disease. It is uncommonly used in lead toxicity due to its potential for serious adverse effects (eg, leukopenia, thrombocytopenia, hepatotoxicity). Educational objective: International adoptees and immigrants should be screened for elevated lead levels due to possible lead exposure in their native country. First-line treatment for asymptomatic, moderate lead toxicity (45-69 μg/dL) is oral meso-2,3-dimercaptosuccinic acid (DMSA, succimer). References: Lead exposure in children: prevention, detection, and management. (http://www.ncbi.nlm.nih.gov/pubmed/16199720) Lead poisoning in children. (http://www.ncbi.nlm.nih.gov/pubmed/20229974)

A 3-Year-Old Boy Is Brought to the Office for a Routine