Pediatric emergency medicine trisk 575

The goal of treatment is the prompt recognition of osteomyelitis in the febrile child with bone pain. The clinical
team should consider advanced imaging by MRI to evaluate for contiguous infections.
Clinical Considerations
Clinical recognition: As the most common bones involved are the femur and tibia, limp is a common presentation.
The multiplicity of bones that may be involved leads to a wide spectrum of chief complaints. Vertebral
osteomyelitis manifests as backache, torticollis, or stiff neck, and involvement of the mandible causes painful
mastication. Infection of the pelvis is particularly elusive and may masquerade as appendicitis, septic hip,
neoplasm, or UTI. Infants with osteomyelitis localize the symptoms less well than older children. Initially,
irritability may be the only complaint.
Fever is seen in 70% to 80% of children with osteomyelitis. The infant with a long bone infection often
manifests pseudoparalysis, an unwillingness to move the extremity. Movement may also be decreased in the older
child, but to a lesser degree. Point tenderness is seen commonly in osteomyelitis; however, it is nonspecific, as it is
found in other conditions, such as trauma, may be difficult to discern in the struggling infant, and does not always
occur early in the course of the infection. Percussion of a bone at a point remote from the site of an osteomyelitis
may elicit pain in the area of infection. When purulent material ruptures through the cortex from a subperiosteal
abscess, diffuse local erythema and edema appear. This finding occurs often in infants, but late in the course, and is
confined primarily to children in the first 3 years of life (before the cortex thickens sufficiently to contain the
inflammatory exudate).
Triage considerations: Any child with fever and a focal bone pain should be evaluated for osteomyelitis.
Associated tachycardia and/or hypotension can imply sepsis and would require fluid resuscitation.
Clinical assessment: Bone biopsy cultures are positive in approximately 60% of children with acute
hematogenous osteomyelitis, and blood cultures are positive in 50% of cases. The ESR and CRP are the most
consistent abnormal laboratory studies and can be used to monitor response to therapy. Plain radiographs of the
affected extremity should be obtained, although they are often normal early in the disease course. Within 3 to 10
days, some radiographic anomalies become evident: muscle edema will obliterate the lucent planes separating
muscle groups. Visualization of bony destruction requires loss of over 40% of the bony matrix, and is a finding
uncommon prior to 10 to 14 days. MRI is used to evaluate for drainable fluid collections (e.g., subperiosteal
abscess or pyomyositis), and the most common finding on MRI in children with osteomyelitis is bone marrow
edema. In the era of MRSA, many centers have noted that some children with osteomyelitis have infected deep
venous thromboses (DVTs) in the adjacent blood vessels. MRI also allows for evaluation of DVTs (which appear
as flow voids). Recognition of DVTs is important, as it could alter antibiotic therapy (e.g., make it more likely to

select a bactericidal antibiotic as opposed to a bacteriostatic drug) and would prompt anticoagulation.
Management: In contrast to septic arthritis, well-appearing children with suspected osteomyelitis do not require
immediate parenteral antibiotic therapy. If a child has age-appropriate vital signs, is previously healthy, and there is
a low likelihood of osteomyelitis, blood cultures and an MRI can be obtained while the child is observed off of
antibiotics. As blood cultures will be positive in only one-half of children, identification of an organism from bone
biopsy is critical. The clinician should immediately contact orthopedic surgery or interventional radiology about
culturing the infected bone prior to initiation of antibiotics in these patients. However, antibiotics should not be
withheld if the child becomes or is toxic-appearing or immunocompromised. Empiric therapy should target S.
aureus. The selection of vancomycin over clindamycin depends upon local antibiotic susceptibility patterns and
any prior culture results available for the child. Nafcillin is a more bactericidal drug for MSSA than vancomycin or
clindamycin and change to a beta-lactam antibiotic (nafcillin or cefazolin) should occur if the child is known to
have MSSA. Coverage should be expanded beyond staphylococcal coverage in immunocompromised children,
children in whom other pathogens have been cultured in the past, and for septic children. Standard precautions
should be used.
Necrotizing Fasciitis
Fasciitis is cellulitis extending to deeper tissues, such as fascia and muscle, but not to bones or joints. The most
common causes in the modern era are GAS and S. aureus. Widespread use of the varicella vaccine has decreased
the incidence of necrotizing fasciitis, where GAS could complicate varicella infection. The family may report that
the lesion is rapidly progressive. Fasciitis can be differentiated from cellulitis by pain out of proportion to
examination findings and more systemic signs; toxic appearance, high fever, tachycardia, and hypotension are
more common. In some cases of anaerobic fasciitis, subcutaneous crepitance may be noted. Patients generally have


a leukocytosis with a neutrophilic predominance, and blood cultures (aerobic and anaerobic) should be obtained, as
bacteremia is present in a majority of cases. Fasciitis is a medical and surgical emergency. Debridement is needed
in many instances to prevent spread to adjacent tissues. Antimicrobial therapy should be targeted toward GAS, S.
aureus, and anaerobes, especially with fasciitis of the head and neck (or any area with evidence of gas production
in the tissues). Multidrug empiric therapy with penicillin (which is more bactericidal for GAS than clindamycin or
vancomycin), clindamycin (for anaerobic coverage), and vancomycin (for MRSA) should be initiated. Contact
precautions should be used.

INFECTIONS IN RETURNED TRAVELERS
Introduction
Over the last 20 years, there has been an enhancement of medical provider networks designed to improve
surveillance and medical care for international travelers. More than 80% of U.S. citizens visiting pretravel clinics
are traveling to resource-poor countries, with Africa being the most commonly visited region. Approximately 38
million residents of the United States traveled internationally in 2017, with approximately 9% reporting travelassociated illnesses. While most are mild, self-limited conditions, such as traveler’s diarrhea, a proportion of these
individuals will present to the ED after returning home. Pediatric travelers may be classified into several groups:
children returning from international travel; children returning from visiting friends and relatives (VFRs) in the
child or parents’ country of origin; international adoptees; and recently emigrated children. These groups may have
distinct risk factors for infection and certain groups (VFRs) historically have been at higher risk for travelassociated infections because their families infrequently seek medical attention prior to international travel.
It is critical for the emergency medicine provider to ask families not only about locations to which the child has
traveled ( Table 94.18 ) for infections common in specific regions, but what regions (e.g., urban vs. rural) the child
visited and what activities were undertaken. Knowing when a child returned home can help determine the possible
incubation period, narrowing the differential diagnosis to certain pathogens. The incubation period and symptoms
of most common diseases in the returned traveler are summarized in Table 94.19 , and the diagnosis and treatment
of these diseases are presented in Table 94.20 . These diseases are categorized in one of three ways: diseases
endemic in both industrialized and developing nations; vaccine-preventable illnesses more common
internationally; and diseases endemic only outside industrialized nations.


TABLE 94.18
GEOGRAPHIC DISTRIBUTION OF INFECTIOUS AGENTS
Region

Pathogens

Africa, sub-Saharan

African tick-bite fever, amebiasis, anthrax, Brucella, Chikungunya, cholera, cutaneous

larval migrans, cysticercosis, dengue, Echinococcus, filariasis, hemorrhagic fever
viruses, hepatitis A, B, and C, leishmaniasis (visceral), malaria, meningococcus,
onchocerciasis, plague, polio, rabies, schistosomiasis, tetanus, trypanosomiasis,
tuberculosis, typhoid and nontyphi Salmonella, yellow fever
Africa, Northern and Anthrax, Brucella, Echinococcus, filariasis, leishmaniasis (cutaneous, visceral), malaria,
Middle East
onchocerciasis, rickettsial disease, tuberculosis
Asia and Indian
subcontinent

Europe, Western

Amebiasis, Angiostrongyliasis, anthrax, Brucella, Chikungunya, cutaneous larval
migrans, cysticercosis, dengue, Echinococcus, filariasis, hepatitis A, B, and C, Japanese
encephalitis, leishmaniasis (visceral), malaria, melioidosis, plague, rabies,
schistosomiasis, tetanus, tick-borne encephalitis, tuberculosis, typhoid
Cholera, cutaneous larva migrans, dengue, diphtheria, filariasis, leishmaniasis
(cutaneous), malaria, melioidosis, typhoid, nontyphi Salmonella , tuberculosis
Amebiasis, anthrax, Brucella, Campylobacter, Chagas disease, cholera, cutaneous larva
migrans, cysticercosis, Echinococcus, filariasis, hepatitis A and B, hemorrhagic fever
viruses, leishmaniasis (visceral cutaneous), leptospirosis, malaria, melioidosis,
onchocerciasis, plague, rabies, Strongyloides, tetanus, typhoid and nontyphi
Salmonella, yellow fever, tuberculosis
Anthrax, Brucella, diphtheria, Echinococcus, hepatitis B and C, polio, tick-borne
encephalitis
Brucella, leishmaniasis (visceral), Lyme disease, meningococcus, tick-borne encephalitis

Mediterranean

Brucella, Echinococcus, hepatitis A, B, and C, rickettsial disease

Caribbean
Central/South
America

Europe, Eastern


TABLE 94.19
EPIDEMIOLOGY, HISTORICAL, AND CLINICAL FINDINGS IN COMMON INFECTIONS IN
RETURNED TRAVELERS