- Pica
- Defined as persistent eating of non-nutritive material
for 1 month or more
- Always search for lead lines in any child with an
ingested foreign body
- Main source of lead intoxication is lead paint used in
houses painted before 1980
- Absorption is greater in children than adults
- Lead may be inhaled as well as ingested
- Symptoms develop more quickly
through GI tract
- Toxicity more severe with
co-existing iron, zinc, or calcium deficiency
- Pathology
- Lead concentrates in metaphyses of growing bones
- Distal femur
- Both ends of tibia
- Distal radius leading to
- Failure of removal of
calcified cartilaginous trabeculae in provisional zone
- Clinical findings
- Neurological
- Learning disability
- Decreased IQ
- Mental retardation
- Encephalopathy
- Motor deficits
- Seizures
- Cerebral edema
- Hearing loss
- Gastrointestinal
- Abdominal pain
- Nausea
- Vomiting
- Diarrhea
- Constipation
- Anorexia
- Metallic taste in mouth
- Ileus
- Renal
- Hematologic
- Affects blood synthesis
- Hemolysis
- RBC stippling
- Iron deficiency
- Musculoskeletal
- Soft tissue
- Blue-black line in gum
margins
- Endocrine
- Decreased stature
- Decreased vitamin D levels
- Laboratory findings
- Imaging findings
- Cerebral edema in acute lead intoxication
- Particles of lead in GI tract
- Bands of increased density at metaphyses of tubular
bones (growing bone)
- Metaphyses of growing bones
may be dense normally
- Lead lines more apt to be
seen in proximal fibula and distal ulna where growth is not as great as
other long bones
- Lead lines may persist
Frontal
radiograph of both knees of a child with lead poisoning show dense metaphyseal
bands
involving not only distal femurs and proximal tibias but proximal fibulas as
well
- Bone-in-bone appearance
- Abnormalities in bone modeling
- Erlenmeyer flask appearance to distal femur
- DDx (see tables below)
- Treatment
- Surgical removal of lead foreign bodies in the gut
(e.g. dice containing lead) if not eliminated within 2 weeks
- Chelation is indicated if the level is greater than 45
mcg/dL even if asymptomatic
- First correct iron deficiency
- Chelating agents include EDTA, BAL, D-Penicillamine,
and Succimer
|
Lucent
Metaphyseal Bands
|
|
Normal
|
|
Leukemia
|
|
Neuroblastoma
|
|
TORCH
infection
|
|
|
Dense
Metaphyseal Bands
|
|
Normal
|
|
Lead
poisoning
|
|
Treated
leukemia
|
|
Healing
rickets
|
|
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