Q 1:
A 12-year-old girl presents to the emergency department for evaluation
of severe headache, fever, and lethargy. The parents note that she first became
ill with an acute upper respiratory illness with congestion and low-grade
fever. The parents also report that over the past few days the girl has had an
elevated temperature of 39.1°C, complaints of increasing frontal headaches
(greater on the left side), and increased sleepiness. On physical examination, the
girl is uncomfortable and awake but sleepy. On examination of head, eyes, ears,
nose, and throat, there is tenderness over the frontal sinuses. Her neck is
supple. Neurologic examination reveals a left sixth cranial nerve palsy. The
remainder of her examination is unremarkable. Computed tomography scan with
contrast reveals pansinusitis with meningeal enhancement over the left
frontoparietal lobe and an epidural collection of approximately 2 cm.
Of the following, the BEST choice for empirical antibiotic therapy,
pending neurosurgical evaluation, is
A. ampicillin and
gentamicin
B. cefazolin and
gentamicin
C. ceftriaxone and
vancomycin
D. metronidazole
and vancomycin
E. nafcillin and vancomycin
Answer:
C
Answer:
C
The
child described in the vignette has a brain abscess documented on computed
tomography scan. Brain abscesses can arise as a complication of a number of
infections through direct extension (eg, sinusitis, mastoiditis, and
odontogenic infections) or hematogenous spread (eg, endocarditis), especially
in children with cyanotic congenital heart disease. Trauma and surgical
procedures are other predisposing factors for development of brain abscesses.
These infections are frequently polymicrobial. Treatment generally involves a
combination of antimicrobial therapy and surgical drainage. Initial empiric
antibiotic therapy depends on the focus of origin and the likely associated
infectious agents.
In
this case, the epidural abscess arose as a direct extension from frontal
sinusitis, so the likely organisms reflect the pathogens of sinusitis:
Streptococcus pneumoniae, Haemophilus influenzae, other streptococcal species,
anaerobes, and, less likely, Staphylococcus aureus. Of the listed regimens,
ceftriaxone and vancomycin provides coverage for these organisms, and these
drugs adequately cross the blood-brain barrier.
Ampicillin
and gentamicin would not provide adequate coverage for ß-lactamase positive H
influenzae, S aureus, or penicillin-resistant S pneumoniae. Additionally,
gentamicin does not adequately cross the blood-brain barrier. Similarly,
first-generation cephalosporins such as cefazolin do not adequately cover H
influenzae and do not cross the blood-brain barrier. The combination of
metronidazole and vancomycin or nafcillin and vancomycin does not provide
adequate coverage, especially for H influenzae.
The
duration of antibiotic therapy for brain abscesses is typically 6 to 8 weeks according
to clinical response. In addition to antibiotic therapy, treatment for brain
abscesses includes consultation with the appropriate specialists and surgical
drainage if indicated.
-------------------
Q 2:
-------------------
Q 2:
An
18-month-old boy is brought to your clinic because of redness of his left cheek
that his mother noticed yesterday. He has been otherwise well and has had no
fever. Physical examination findings reveal a tender, erythematous area of
slight induration on his left cheek . His mother tells you that the
boy recently started sucking ice chips.
Of
the following, the MOST likely diagnosis is
A. cellulitis
B. cold panniculitis
C. dental abscess
D. juvenile xanthogranuloma
E. lipoma
Answer
B
Answer
B
Cold
panniculitis, also known as “popsicle panniculitis,” is a lesion of the skin
caused by prolonged exposure to cold objects. Sucking on popsicles or ice chips
results in the most common presentation on the cheeks, but any area of the body
exposed to cold can be affected. The mechanism of pathogenesis is similar to
that of fat necrosis and likely occurs because in infants the subcutaneous fat
is more apt to solidify than in adults.
Typical
lesions are bluish red nodules that may be painful. They usually arise within 1
to 2 days of cold exposure, and they may persist for several weeks. Although
rarely required for diagnosis, histologic examination reveals histiocytic and
lymphoid cells within fat lobules. Because the lesions resolve within weeks, no
treatment is necessary. However, it is advisable to avoid cold exposure if
possible.
Cellulitis
is suppurative inflammation of the skin caused by bacteria, such as
Streptococcus pyogenes and Staphylococcus aureus. A child who has cellulitis is
often febrile, and his skin is very tender, erythematous, and warm to the
touch. A dental abscess could cause painful swelling of the cheek, but fever
and tenderness over the gingiva and affected tooth would be expected. Juvenile
xanthogranuloma is characterized by yellowish or brownish nodules on the skin, and the lesions are typically present from birth or early infancy.
A lipoma, a benign tumor of fat cells, may be found anywhere on the body but
typically does not cause tenderness or skin discoloration.
-----------------------------------------
Q 3:
-----------------------------------------
Q 3:
A
6-year-old girl who has corrected congenital heart disease and a history of
furunculosis presents to the emergency department with fever and increased work
of breathing. Physical examination reveals a temperature of 39.5°C, heart rate
of 130 beats/min, respiratory rate of 30 breaths/min, and blood pressure of
85/55 mm Hg. Her oxygen saturation is 90% in room air. A new blowing murmur is
noted on cardiac examination, and auscultation of the chest reveals diffuse
crackles bilaterally. She has hepatosplenomegaly and a capillary refill of 3 to
4 seconds. Her skin examination yields normal results. Her white blood cell
count is 30.0 × 103/µL (30.0 × 109/L), with 71% polymorphonuclear leukocytes,
23% lymphocytes, and 6% monocytes. Chest radiograph shows diffuse pulmonary
interstitial edema.
Of
the following, the MOST appropriate initial antibiotic therapy for this patient
is
A.
ampicillin-sulbactam
B.
ceftazidime
C.
doxycycline
D.
trimethoprim-sulfamethoxazole
E. vancomycin
Answer
E
Answer
E
The
patient described in the vignette presents with clinical sepsis, and her
history of corrected congenital heart disease and furunculosis in conjunction
with fever and a new murmur on physical examination strongly suggests acute
infectious endocarditis (IE). In children with a fulminant presentation of IE,
Staphylococcus aureus is the most common cause. Therefore, prompt initiation of
antimicrobial therapy with a bactericidal agent such as vancomycin is warranted.
---
Q 3:
A 3-year-old patient who has acute lymphoblastic leukemia is admitted to the pediatric intensive
care unit after developing severe sepsis due to Pseudomonas aeruginosa. She is intubated,
ventilated, and requires intensive vasopressor support.
Of the following, the MOST appropriate antibiotic regimen for the treatment of this patient is an
aminoglycoside plus
A. cefazolin
B. cefdinir
C. ceftazidime
D. ceftriaxone
E. cefuroxime
Answer
C
Serious P aeruginosa infections, such as bacteremia, sepsis, and pneumonia, are more
likely in patients who have underlying conditions, especially cystic fibrosis. Initial therapy usually
consists of two antipseudomonal agents, such as a beta-lactam antibiotic (piperacillin, piperacillintazobactam,
or ceftazidime) plus an aminoglycoside (gentamicin, tobramycin, or amikacin) until
results of susceptibility tests are available
----------------------
Q 4 :
A 10-year-old boy presents with a 1-day history of fever and a swollen leg. According to his
mother, the boy developed a small abrasion on his leg while playing outside 3 days ago. Last
night he began to complain of pain in the area and had a low-grade fever. This morning his
temperature was 102.4°F (39.1°C) and the area around the abrasion looked very red and was
tender to palpation. About 2 hours later, the swelling had increased. Physical examination
reveals a boy in no apparent distress who has a temperature of 101.4°F (38.6°C), a heart rate of
93 beats/min, a respiratory rate of 23 breaths/min, and a blood pressure of 95/65 mm Hg. All
other findings are normal, except for a small erythematous abrasion just above the medial
malleolus that has no discharge. Erythema from this area extends to a well-demarcated region
of the mid-calf and is tender to touch .
Of the following, the MOST likely pathogen is
A. Pseudomonas aeruginosa
B. Staphylococcus aureus
C. Streptococcus pneumoniae
D. Streptococcus pyogenes
E. Vibrio vulnificans
.Answer:
D
Cellulitis is an infection and inflammation of the connective tissue that involves the dermis and often is preceded by a break in the skin. Cellulitis also can be seen in patients who have an underlying condition that predisposes them to such an illness (eg, lymphatic stasis, diabetes mellitus).
Streptococcus pyogenes and Staphylococcus aureus are the two most common bacterial agents responsible for the development of this infection.
Although distinction between the two pathogens is difficult, the rapidly spreading erythema without purulence described for patient in the vignette is most consistent with S pyogenes infection .
Infections caused by S aureus tend to be more localized and produce purulent material. Confirmation of the
etiologic agent requires recovery of the organism from an aspirate of the most erythematous area or a culture from purulent exudates or from the blood.
For most patients, initial empiric therapy is with an antimicrobial agent that has activity
against both of these gram-positive cocci. Empiric treatment courses have changed recently,
with the increased prevalence of methicillin-resistant S aureus (MRSA). Mild forms of cellulitis
may be treated with a topical antimicrobial ointment (eg, mupirocin). More advanced cases
require the addition of an oral antimicrobial agent such as clindamycin, trimethoprimsulfamethoxazole,
or doxycycline in geographic areas that are highly endemic for MRSA.
---------------
Q 5:
You are evaluating a previously healthy 3-year-old boy for a 3-day history of nausea; vomiting;
and profuse watery, nonbloody diarrhea that has worsened over the last 24 hours. He can keep
down water and an oral electrolyte maintenance solution but has no interest in eating solid food.
On physical examination, the tired-appearing little boy has a temperature of 100.8°F (38.3°C), moist
mucous membranes, and a soft abdomen with mild diffuse tenderness to palpation. Laboratory
tests document a peripheral white blood cell count of 6.7x103/mcL (6.7x109/L); hemoglobin of
12.0 g/dL (120.0 g/L); platelet count of 230.0x103/mcL (230.0x109/L); and a differential count of
50% neutrophils, 40% lymphocytes, and 10% monocytes.
Of the following, the MOST likely pathogen causing this patient’s condition is
A. Campylobacter jejuni
B. Escherichia coli
C. Giardia lamblia
D. Salmonella sp
E. Shigella sp
---
Q 3:
A 3-year-old patient who has acute lymphoblastic leukemia is admitted to the pediatric intensive
care unit after developing severe sepsis due to Pseudomonas aeruginosa. She is intubated,
ventilated, and requires intensive vasopressor support.
Of the following, the MOST appropriate antibiotic regimen for the treatment of this patient is an
aminoglycoside plus
A. cefazolin
B. cefdinir
C. ceftazidime
D. ceftriaxone
E. cefuroxime
Answer
C
Serious P aeruginosa infections, such as bacteremia, sepsis, and pneumonia, are more
likely in patients who have underlying conditions, especially cystic fibrosis. Initial therapy usually
consists of two antipseudomonal agents, such as a beta-lactam antibiotic (piperacillin, piperacillintazobactam,
or ceftazidime) plus an aminoglycoside (gentamicin, tobramycin, or amikacin) until
results of susceptibility tests are available
----------------------
Q 4 :
A 10-year-old boy presents with a 1-day history of fever and a swollen leg. According to his
mother, the boy developed a small abrasion on his leg while playing outside 3 days ago. Last
night he began to complain of pain in the area and had a low-grade fever. This morning his
temperature was 102.4°F (39.1°C) and the area around the abrasion looked very red and was
tender to palpation. About 2 hours later, the swelling had increased. Physical examination
reveals a boy in no apparent distress who has a temperature of 101.4°F (38.6°C), a heart rate of
93 beats/min, a respiratory rate of 23 breaths/min, and a blood pressure of 95/65 mm Hg. All
other findings are normal, except for a small erythematous abrasion just above the medial
malleolus that has no discharge. Erythema from this area extends to a well-demarcated region
of the mid-calf and is tender to touch .
Of the following, the MOST likely pathogen is
A. Pseudomonas aeruginosa
B. Staphylococcus aureus
C. Streptococcus pneumoniae
D. Streptococcus pyogenes
E. Vibrio vulnificans
.Answer:
D
Cellulitis is an infection and inflammation of the connective tissue that involves the dermis and often is preceded by a break in the skin. Cellulitis also can be seen in patients who have an underlying condition that predisposes them to such an illness (eg, lymphatic stasis, diabetes mellitus).
Streptococcus pyogenes and Staphylococcus aureus are the two most common bacterial agents responsible for the development of this infection.
Although distinction between the two pathogens is difficult, the rapidly spreading erythema without purulence described for patient in the vignette is most consistent with S pyogenes infection .
Infections caused by S aureus tend to be more localized and produce purulent material. Confirmation of the
etiologic agent requires recovery of the organism from an aspirate of the most erythematous area or a culture from purulent exudates or from the blood.
For most patients, initial empiric therapy is with an antimicrobial agent that has activity
against both of these gram-positive cocci. Empiric treatment courses have changed recently,
with the increased prevalence of methicillin-resistant S aureus (MRSA). Mild forms of cellulitis
may be treated with a topical antimicrobial ointment (eg, mupirocin). More advanced cases
require the addition of an oral antimicrobial agent such as clindamycin, trimethoprimsulfamethoxazole,
or doxycycline in geographic areas that are highly endemic for MRSA.
---------------
Q 5:
You are evaluating a previously healthy 3-year-old boy for a 3-day history of nausea; vomiting;
and profuse watery, nonbloody diarrhea that has worsened over the last 24 hours. He can keep
down water and an oral electrolyte maintenance solution but has no interest in eating solid food.
On physical examination, the tired-appearing little boy has a temperature of 100.8°F (38.3°C), moist
mucous membranes, and a soft abdomen with mild diffuse tenderness to palpation. Laboratory
tests document a peripheral white blood cell count of 6.7x103/mcL (6.7x109/L); hemoglobin of
12.0 g/dL (120.0 g/L); platelet count of 230.0x103/mcL (230.0x109/L); and a differential count of
50% neutrophils, 40% lymphocytes, and 10% monocytes.
Of the following, the MOST likely pathogen causing this patient’s condition is
A. Campylobacter jejuni
B. Escherichia coli
C. Giardia lamblia
D. Salmonella sp
E. Shigella sp
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