Pediatric emergency medicine trisk 572

Kawasaki disease (KD) is the most common form of acquired heart disease in children in
industrialized nations.
KD is a clinical diagnosis in a child with fever to 102°F for at least 5 days who has four of five
additional symptoms: oral mucosal changes; rash; nonpurulent conjunctivitis; extremity changes; and
cervical lymphadenopathy.
Incomplete KD, where children do not meet all the diagnostic criteria, is more common in young
infants, and is a risk factor for the development of coronary artery aneurysms (CAAs).
Current Evidence
KD is a vasculitic condition of unknown etiology that can cause CAAs or ectasia in up to 25% of untreated
children. It is the most common form of acquired heart disease in American children. While first described in
Japanese children, it occurs in children of all races and ethnicities and is most common in infants and preschoolaged children. Older children are also at risk for CAA, as diagnosis is often delayed in this group.
Goals of Treatment
The goal of treatment is to recognize and initiate treatment in children with KD before the 10th day of symptoms,
as delayed treatment increases the risk of CAA development.
Clinical Considerations
Clinical recognition: The symptoms of KD are summarized in Table 94.15 . Incomplete KD, in which a child does
not meet all diagnostic criteria, is more common in infants and rates of CAA are higher in children with
incomplete KD. It is important that clinicians ask all caregivers of children with fever of at least 5 days duration
about KD symptoms. Not all symptoms may be present at the time of ED presentation. The differential diagnosis
of KD is extensive and includes viral infections (especially adenovirus, but can also include EBV, cytomegalovirus
[CMV]), scarlet fever, staphylococcal-scalded skin syndrome, TSS, rickettsial diseases (e.g., RMSF), leptospirosis,
drug hypersensitivity reactions, and some rheumatologic conditions.
Triage considerations: Children with KD can be intravascularly depleted from insensible losses from several
days of high fever. Fluid resuscitation may be needed in the ED. If there is concern for cardiac function based upon
examination (e.g., murmur, hepatomegaly), fluid resuscitation should proceed cautiously and early cardiac imaging
(or a baseline electrocardiogram) should be obtained.


TABLE 94.15
CLINICAL AND LABORATORY FINDINGS IN KAWASAKI DISEASE

Clinical assessment: Supporting laboratory criteria are described in Table 94.24 . In children with elevated
inflammatory markers with at least 5 days of fever and 2 or 3 clinical criteria, or in infants with at least 7 days of
fever without explanation, incomplete KD should be suspected if the children have at least three associated
laboratory findings: leukocytosis (≥15,000/mm3); anemia; thrombocytosis (≥450,000/mm3), hypoalbuminemia
(≤3 g/dL), elevated ALT, or pyuria (≥10 WBC/HPF).
Management: The treatment for KD is intravenous immunoglobulin (IVIG) at 2 g/kg as a single dose given over
10 to 12 hours. In addition, children should be started on high-dose aspirin (80 to 100 mg/kg/day divided every 6
hours). An echocardiogram should be ordered. A clinician’s threshold for treating should be lower as a child
approaches day 10 of fever than it is at day 5. Standard precautions should be used.

Other Cardiac Infectious Emergencies
Goals of Treatment
ED recognition of new cardiac infections is poor, especially in the child without pre-existing structural heart
disease. For example, most children with myocarditis are missed at the time of initial ED presentation. Recognition
of children at risk for endocarditis, as well as the most common manifestations of myocarditis and pericarditis, can
prevent the ED physician from inadvertently worsening cardiac function from rapid fluid resuscitation.
CLINICAL PEARLS AND PITFALLS
Infective endocarditis is most common in children with structural heart disease, but increased rates of
S. aureus endocarditis in children with normal heart valves have recently been described.
The most common sign of myocarditis is unexplained tachycardia.
The chest radiograph in a child with pericarditis and a large pericardial effusion may be normal.
Bedside ultrasound can provide rapid assessment for pericardial effusion and contractility.


Endocarditis
Endocarditis is an infection of cardiac valves most commonly caused by S. aureus, viridans streptococci, the socalled HACEK organisms (Haemophilus noninfluenzae species, Actinobacillus actinomycetemcomitans,
Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae ), and Coxiella (Q-fever). Endocarditis is
more common in children with existing structural heart disease. The most common symptoms are fever, chills,
fatigue, myalgias, and examination findings may include evidence of embolic phenomenon (pulmonary infarcts,
intracranial or subconjunctival hemorrhages), Janeway lesions (nontender hemorrhagic macules on palms/soles),

immunologic phenomenon (glomerulonephritis, Osler nodes [red, tender raised lesions on palms/soles], or Roth
spots [white-centered retinal hemorrhages]). The diagnosis is based on the modified Duke criteria, which combine
major criteria (blood culture positivity with an organism known to cause endocarditis; echocardiogram findings)
with minor criteria, which include predisposing structural heart disease, fever, and embolic or immunologic
phenomenon. ED-based diagnosis involves obtaining several large-volume blood cultures before antibiotics are
initiated to optimize culture yield. The laboratory should be instructed to hold the blood cultures for several weeks,
as some of the organisms causing endocarditis are fastidious. Empiric management in the critically ill child with
suspected endocarditis should cover MRSA and gram-negative organisms (e.g., with bactericidal antibiotics such
as vancomycin and cefotaxime). Standard precautions should be used.
Myocarditis
Myocarditis is a variably painful inflammation of the myocardium primarily caused by viral infections, most
commonly enteroviruses, but parvovirus, influenza, parainfluenza, and adenovirus, and other viruses can also
cause myocarditis. In children with a consistent travel history, Chagas disease (Trypanosoma cruzi ) and parasitic
infections can also cause myocarditis. Myocarditis has been found in 15% to 20% of sudden infant death syndrome
victims and the same proportion of adolescents who suffer from sudden cardiac death. Early symptoms mimic the
nonspecific findings of viral infections; the most common symptoms are shortness of breath, vomiting, poor
feeding, rhinorrhea, and fever. Chest pain is more commonly verbalized by older children. The most common
examination findings are tachypnea, hepatomegaly, fever, and crackles. Findings may become more obvious after a
child receives fluid boluses, emphasizing the importance of serial examinations between fluid boluses. EKGs are
abnormal in over 90% of patients; the most common EKG findings are sinus tachycardia, low-voltage QRS
complexes, and T-wave inversion. Chest radiographs are abnormal in 60% to 90% of children, most commonly
showing cardiomegaly and pulmonary edema. Laboratory evaluation should include troponin, creatine kinase MB,
B-type natriuretic peptide (BNP), and early cardiology intervention should be sought. Standard precautions should
be used.
Pericarditis is caused by a more heterogeneous group of pathogens (enterovirus being the primary viral etiology,
while pneumococcus, meningococcus, S. aureus, and tuberculosis are among the more common bacterial causes).
Rheumatologic disorders, uremia, pancreatitis, and other noninfectious etiologies can also result in pericardial
inflammation. Symptoms are nonspecific and include fever, cough, shortness of breath, abdominal pain, and
vomiting. Chest pain is an early finding, is worst over the precordium, may radiate to the left shoulder, is worse
when supine, and alleviated when the child is sitting upright or leaning forward. Examination findings include a

pericardial friction rub, muffled heart tones, tachycardia, jugular venous distension (JVD), and narrowed pulse
pressures. Pulsus paradoxus, where the systolic blood pressure decreases by >10 mm Hg with inspiration, is
concerning for tamponade physiology. Beck triad is pathognomonic for tamponade: JVD, muffled heart sounds,
and hypotension. EKGs are abnormal in >90%. Diffuse ST elevation is seen first, followed by ST depression and
PR decrease, then normalization of intervals with T-wave inversions. As the pericardial effusion increases, QRS
voltages are dampened and there may be evidence of electrical alternans. The chest radiograph often is normal in
pericarditis, as it is estimated that an effusion has to be at least 250 mL (in adults) before being apparent on plain
radiograph. Early cardiology intervention and echocardiogram are critical. Nonsteroidal anti-inflammatory drugs
are the mainstay of pericarditis treatment. Children with tamponade physiology may require pericardiocentesis.
Standard precautions should be used.

GASTROINTESTINAL INFECTIOUS EMERGENCIES
Gastroenteritis is an inflammation of the alimentary tract that, in its acute form, is overwhelmingly infectious in
origin. Viruses are the organisms most commonly found in children with diarrhea in the United States and can be
isolated from approximately 30% of patients. In 10% of patients, bacteria are recovered, including Salmonella,
Shigella, Campylobacter, Yersinia, and pathogenic E. coli. Clostridium difficile, which elaborates a toxin, may


cause colitis, particularly after the use of antibiotics. Parasitic infestations rarely lead to diarrhea in developed
countries. Giardia lamblia and Cryptosporidium should be considered, particularly in outbreaks in daycare centers,
and Entamoeba histolytica, among immigrants or travelers from tropical areas; cryptosporidiosis also commonly
affects patients with HIV. These topics are covered later in this chapter, in the sections on travel medicine and HIV,
respectively. Current diagnostic techniques are unable to identify an etiologic agent in most of the remaining
episodes.
Viral hepatitis is covered in Chapter 91 Gastrointestinal Emergencies . Bacterial infections of the liver and
bacterial cholangitis, almost exclusively abscesses, are rare in otherwise healthy children; more commonly, they
complicate either an anatomic malformation (e.g., biliary atresia) or affect neonates or immunocompromised hosts.
Because calculi in the bile ducts rarely occur before adolescence, cholecystitis occurs much less often in
children than in adults. Occasionally, episodes are seen in teenagers or children predisposed to stone formation, as
in the chronic hemolytic anemias. Less commonly, salmonellosis, leptospirosis, or KD produces acalculous

cholecystitis. These diseases are discussed elsewhere in this chapter.
In childhood, peritonitis almost invariably reflects an intra-abdominal catastrophe that requires surgical
intervention. However, the accumulation of ascitic fluid in children with diseases such as nephrosis and cirrhosis
allows the development of a primary infection of the peritoneum.

Gastroenteritis—Viral
The most common etiologies of acute gastroenteritis (AGE) in the United States are viral, most commonly
noroviruses and rotavirus, which comprise almost 40% of viral AGE in the United States. Rotavirus has been on a
major decline since the introduction of routine vaccination. Please also see Chapter 23 Diarrhea . Adenovirus,
sapovirus, astrovirus, parechovirus, and bocavirus comprise an additional 30% of cases in preschool-aged children.
Most causes of viral gastroenteritis are self-limited in healthy children; however, young children can shed viruses
in feces for weeks to months after acute infection, contributing to secondary spread in the community. The most
common symptoms are diarrhea and/or vomiting, crampy abdominal pain, and fever. Signs on examination may
include pyrexia, tachycardia, and hyperactive bowel sounds. Hematochezia and high fever in the older child may
suggest a bacterial etiology, as would a history of international travel to a developing nation. No laboratory studies
are indicated in uncomplicated gastroenteritis in the previously healthy child with mild dehydration. Fecal
leukocytes or stool lactoferrin is more indicative of a bacterial pathogen.

Gastroenteritis—Bacterial
Five bacterial pathogens commonly produce gastroenteritis: Salmonella, Shigella, Yersinia, Campylobacter, and
pathogenic E. coli (Campylobacter, typhoid fever, and pathogenic E. coli are discussed in the travel medicine
section of this chapter). Together, these organisms cause approximately 10% of the diarrheal illnesses seen in
children coming to the ED. In underdeveloped countries and occasionally in the United States, Vibrio species must
also be considered. C. difficile causes toxin-associated colitis, particularly in patients who receive antibiotics. The
most common antibiotic associated with C. difficile is amoxicillin.
Salmonella, Shigella, Yersinia, and Campylobacter do not normally inhabit the alimentary tract. Thus, recovery
of one of these organisms suffices for the diagnosis of gastroenteritis. E. coli, however, is part of the normal bowel
flora, only occasionally assuming a pathogenic role. Serotyping is useful for detecting E. coli O157:H7, which
along with related strains is capable of inducing hemolytic uremic syndrome (HUS), but identification of other
disease-producing strains is not readily available to the clinician.

Hemolytic Uremic Syndrome
Shiga toxin-producing E. coli (STEC) can cause HUS and colitis. The most common serotype causing HUS in the
United States is E. coli O157:H7, but Shigella, Campylobacter, and pneumococcus have also been associated with
HUS. The pathogen is spread via fecal–oral transmission, and recent cases have been linked to contaminated fruits
and vegetables, undercooked beef, and use of community pools. While HUS is rare, the morbidity and mortality
are substantial and the disease can be difficult to diagnose in the early stages. Children present with bloody
diarrhea, followed 5 to 10 days later by hematuria, oliguria, and altered mental status. Laboratory findings include
elevated BUN and creatinine, thrombocytopenia, and anemia. The CDC case definition specifies that anemia must
be accompanied by microangiopathic changes (e.g., schistocytes, burr cells, or helmet cells on peripheral smear),
and that renal involvement may consist of hematuria, proteinuria, and elevated creatinine (≥1 mg/dL in children
<13 years of age and ≥1.5 mg/dL in older children). Thrombocytopenia, not part of the case definition, is an early