Pediatric Examination and Board Review (109 page)

7.
(C)
Of those listed, the only one not seen in acute or chronic lead poisoning is advanced pubertal development. Mildly elevated blood lead levels have been associated with delayed breast and pubic hair development and decreased height in girls.

8.
(C)
Currently the CDC recommends retesting lead levels in 3 months if the lead level is 10-19 μg/dL. Nutritional and environmental counseling should be initiated in any patient with a level greater than 14 μg/dL. Chelation is not warranted at this lead level. Iron therapy, although controversial during IV chelation therapy for lead poisoning, is nevertheless recommended in patients with documented iron deficiency anemia.

9.
(C)
Standard chelation should be used if the lead level is 45 μg/dL or higher. According to CDC recommendations, a level of 45 μg/dL or higher should be repeated and verified within 48 hours.

10.
(E)
Chelation can be given orally or parenterally. Some form of chelation is begun at a level of 45 μg/dL or higher, with parenteral treatment in the hospital setting started for a level of 70 μg/dL or higher. The oral chelation agent used is DMSA (succimer), which can be given initially for 19 days. This chelation must occur in a lead-free environment. Parenteral chelation, which can be begun at levels 45 μg/dL or higher, includes calcium disodium EDTA and BAL simultaneously. BAL is toxic when given with iron.

11.
(D)
Side effects of BAL include fever, tachycardia, hypertension, salivation, tingling around the mouth, anaphylaxis, and hemolysis in G6PD patients.

12.
(C)
Hepatic insufficiency is a contraindication to BAL/dimercaprol therapy. Peanut allergy is also a contraindication because BAL/dimercaprol is dissolved in peanut oil for administration. BAL administration should be used cautiously in those with renal impairment and in the presence of G6PD.

13.
(B)
All of the above historically have been noted to contain lead, although food cans have been lead free since U.S. legislation in 1977 limited lead in household paint and gasoline. This legislation also stopped the soldering of cans for food. The remaining items are all still possible sources of lead.

14.
(E)
All of the given answers are independent risk factors for elevated blood lead level.

15.
(A)
Recommendations for prevention of lead intoxication include a balanced diet with frequent meals that are high in iron, vitamin C, and calcium, all of which compete with lead for GI absorption.

16.
(C)
Ion-exchange and reverse-osmosis filters, as well as distillation, are effective in removing lead from water sources. However, glass and carbon filters, the most common ones found in homes, do not remove heavy metals, including lead.

17.
(D)
The American Heart Association recommends cholesterol screening for patients older than 2 years who have a parent or grandparent with documented premature cardiovascular disease (angina, MI, sudden cardiac death, cerebrovascular disease, coronary bypass, angioplasty, or peripheral vascular disease that occurred when younger than 55 years), a parent with documented hypercholesterolemia, or an unknown family history.

18.
(A)
Immediate testing should be performed on (1) contacts of anyone with confirmed or suspected TB, (2) children with radiographic or clinical findings of TB, (3) children immigrating from endemic countries (eg, Asia, Middle East, Africa, Latin America), and (4) children with travel histories to endemic countries and/or significant contact with indigenous peoples.

19.
(C)
By the age of 2 years, according to the Denver II, children should be able to kick a ball forward. The remaining choices are all within normal range of abilities for a 2-year-old.

S
UGGESTED
R
EADING

Campbell C, Osterhoudt KC. Prevention of childhood lead poisoning.
Curr Opin Pediatr.
2000;12:428-437.

Markowitz M. Lead poisoning.
Pediatr Rev.
2000;21:327-335.

Wright RO, Tsaih S-W, Schwartz J, Wright RJ, Hu H. Association between iron deficiency and blood level in a longitudinal analysis of children followed in an urban primary care clinic.
J Pediatr.
2003;142:9-14.

Wu AC, Lesperance L, Bernstein H. Screening for iron deficiency.
Pediatr Rev.
2002;23:171-178.

CASE 67: A 2-YEAR-OLD WHO REFUSES TO WALK

A 2-year-old boy presents to the emergency department with a 1-day history of refusing to walk. Mom reports that she had first noticed him limping slightly 3-4 days ago, but he was otherwise well. He was not complaining of pain, but Mom noticed that when he stood, he did not bear weight on his right leg. On the day of admission she noticed that he refused to walk. She denies a history of bites or specific trauma, but she does admit that he is “always running into things.” He had a cough and congestion the previous week and has “felt warm” for 1-2 days but has otherwise been well. She denies any preceding sore throat or rash.

On examination the patient is fussy and uncooperative. His temperature is 101.3°F (38.5° C) rectally, HR 115, RR 22, and BP normal. He has no rashes or discolorations of his skin and is well hydrated. He refuses to ambulate. On musculoskeletal examination the patient has a tender, warm, and swollen right knee. There is mild erythema but no induration. He resists range of motion activities at the knee but has full range of motion and no tenderness on examination of the hip. Otherwise his examination is unremarkable.

SELECT THE ONE BEST ANSWER

1.
All are appropriate choices for initial workup except

(A) bone scan

(B) hip and knee films

(C) CBC with differential

(D) ESR

(E) CRP

2.
The plain films demonstrate soft tissue swelling surrounding the knee, but no findings consistent with fracture or osteomyelitis. The hip x-ray is normal. The CBC shows a leukocyte count of 18.4 × 10
³
with 28% bands; the ESR is 68 mm/hour, and the CRP is 94 mg/L. Which of the following is least likely in the differential at this point?

(A) osteomyelitis

(B) transient synovitis

(C) septic arthritis

(D) cellulitis

(E) postinfectious arthritis

3.
What would be the best test/procedure to diagnose a septic joint?

(A) urine antigen detection test

(B) ultrasound

(C) CRP

(D) joint aspiration

(E) MRI

4.
The patient’s ultrasound demonstrates no effusion, and osteomyelitis is now strongly suspected. What is the most likely causative organism morphology and biochemical reaction?

(A) gram-negative bacilli without lactose fermentation

(B) gram-positive cocci in chains

(C) gram-negative bacilli without sucrose fermentation

(D) gram-negative coccobacilli

(E) gram-positive cocci in clusters

5.
Knowing the likely pathogens for osteomyelitis, in a region where MRSA isolates are common, what would be an appropriate empirical therapy?

(A) clindamycin

(B) penicillinase-resistant penicillin

(C) third-generation cephalosporin

(D) combination of A and C

(E) combination of B and C

6.
Which of the following is the most specific method for confirmatory diagnosis of osteomyelitis?

(A) MRI

(B) conventional radiograph

(C) bone scan

(D) needle aspirate of the bone

(E) CT scan

7.
Which of the following is the most common pathogenesis of osteomyelitis in children?

(A) contiguity

(B) direct invasion

(C) hematogenous spread

(D) unknown

(E) B and C are approximately equal

8.
All of the following are complications of osteomyelitis except

(A) fracture

(B) septic joint

(C) subperiosteal abscess

(D) leg shortening

(E) no exceptions; all of the above are complications of osteomyelitis

9.
Which of the following is the most common site of septic arthritis in children older than 1 year?

(A) ankle

(B) shoulder

(C) wrist

(D) knee

(E) hip

10.
Which of the following is the cornerstone of the diagnosis of septic arthritis?

(A) MRI

(B) plain films

(C) blood culture

(D) presence of warmth at the affected joint

(E) arthrocentesis and fluid culture