Lead intoxication may cause developmental and behavioralabnormalities that are not reversible, even if the hematologicand other metabolic complications are treated. Although theCenters for Disease Control and Prevention (CDC) recommends environmental investigation at blood lead levels of20 μg/dL on a single visit or persistent 15 μg/dL over a 3-month period, levels of 5 to 10 μg/dL may cause learning problems. Risk factors for lead intoxication include living in older homes withcracked or peeling lead-based paint, industrial exposure, use offoreign remedies (e.g., a diarrhea remedy from Central or SouthAmerica), and use of pottery with lead paint glaze. Because ofthe significant association of lead intoxication with poverty, theCDC recommends blood lead screening at 12 and 24 months.In addition, standardized screening questions for risk of leadintoxication should be asked for all children between 6 months and 6 years of age (Table 9-2). Any positive or suspect responseis an indication for obtaining a blood lead level. Capillary bloodsampling may produce false-positive results, thus, a venousblood sample should be obtained. County health departments,community organizations, and private companies provide leadinspection and detection services to determine the source of thelead. Standard decontamination techniques should be used toremove the lead while avoiding aerosolizing the toxic metal thata child might breathe or creating dust that a child might ingest(see Chapters 149 and 150).
The prevalence of tuberculosis is increasing, largely as a resultof the adult human immunodeficiency virus (HIV) epidemic.Children often present with serious and multisystem disease(miliary tuberculosis). All children should be assessed for risk oftuberculosis at health maintenance visits, especially after 1 yearof age. The high-risk groups, as defined by the CDC, are listedin Table 9-3. In general the standardized purified protein derivative intradermal test is used with evaluation by a health care provider 48 to 72 hours after injection. The size of induration, notthe color of any mark, denotes a positive test. For most patients,
Does the child spend any time in a building built before 1960 (e.g., home, school, barn) that has cracked or peeling paint?
Is there a brother, sister, housemate, playmate, or community member being followed or treated (or even rumored to be) for lead poisoning?
Does the child live with an adult whose job or hobby involves exposure to lead (e.g., lead smelting and automotive radiator repair)?
Does the child live near an active lead smelter, battery recycling plant, or other industry likely to release lead?
Does the family use home remedies or pottery from another country?
Close contact with persons known to have tuberculosis (TB), positive TB test, or suspected to have TB
Foreign-born persons from areas with high TB rates (Asia, Africa, Latin America, Eastern Europe, Russia)
High-risk racial or ethnic minorities or other populations at higher risk (Asian, Pacific Islander, Hispanic, African American, Native American, groups living in poverty [e.g., Medicaid recipients], migrant farm workers, homeless persons, substance abusers)
Infants, children, and adolescents exposed to adults in high-risk categories 10 mm of induration is a positive test. For HIV-positive patients,those with recent tuberculosis contacts, patients with evidenceof old healed tuberculosis on chest film, or immunosuppressedpatients, 5 mm is a positive test (see Chapter 124). The CDC hasapproved (in adults) the QuantiFERON-TB Gold Test, whichhas the advantage of needing one office visit only.