Pediatric emergency departments often see children with a wide range of conditions, from mild illnesses to life-threatening diseases. It’s helpful when serious conditions like volvulus present with clear and obvious symptoms, such as bilious emesis in a newborn. However, the challenge—and anxiety—arises when an urgent or emergent condition mimics a more benign presentation. Two such conditions that are commonly missed on initial evaluation:
Case 1: An 11-month-old presents with 10 days of fever. Initially diagnosed with otitis media and later treated for a presumed allergic reaction due to a rash, the child returned five days later with hand and feet swelling, gum swelling, and cracked lips. Labs revealed anemia, thrombocytosis, and elevated inflammatory markers
Diagnosis: Kawasaki Disease
Kawasaki Disease is the most common cause of acquired heart disease in children in developed countries. Timely initiation of intravenous immunoglobulin (IVIG) by day 10 can dramatically reduce the incidence of coronary artery aneurysms from 25% to 4%. However, KD is frequently missed, especially in cases where co-infections or incomplete symptoms are present.
Pitfalls to avoid:
- Co-Infections: A positive respiratory viral panel should never rule out KD. Studies show that over 40% of children with KD also test positive for other infections, like RSV. Even substantial co-infections such as Group A Strep or pneumonia should not sway you from a KD diagnosis if the clinical criteria for KD are met.
- Atypical KD: A significant proportion of KD cases are atypical, meaning they present with fewer classic symptoms. These atypical cases account for 50% of missed diagnoses. Incomplete KD can present with just two clinical criteria and five days of fever, making it trickier to diagnose. Clinicians must maintain a high level of suspicion, especially in children under five with prolonged fever.
- Symptoms Don’t Always Present Together: KD symptoms often appear at different times. A rash may resolve before a child presents to the ED, which can lead to a missed diagnosis if the history is not thoroughly obtained. Asking parents about any symptoms that have occurred during the course of the illness is critical.
Case 2: A 12-year-old boy presents with one day of vomiting and four days of URI symptoms. Initially diagnosed with gastroenteritis, he was sent home after his heart rate improved slightly following a bolus and Zofran. Hours later, he returned in hypotensive shock
Diagnosis: Myocarditis
Myocarditis, or inflammation of the heart muscle, is the most common cause of heart failure in otherwise healthy children. It’s dangerous yet subtle, especially in younger children who often present with non-cardiac symptoms.
The Challenge:
- Age-Based Presentation: Myocarditis has a bimodal distribution, peaking in children under six and over 13 years of age. Older children are more likely to present with classic cardiac symptoms like chest pain, but younger children often present with respiratory or GI symptoms, such as vomiting, diarrhea, and abdominal pain. This variability in presentation can easily lead to missed diagnoses.
- No Sensitive Test: There is no single test that reliably diagnoses myocarditis. Troponin, often thought of as the gold standard for cardiac injury, is normal in about half of pediatric myocarditis cases. Similarly, EKG and chest x-ray findings are highly variable. The most common EKG finding is sinus tachycardia, which is often overlooked in the ED. However, pooling the sensitivity of all available tests (EKG, chest x-ray, labs) is your best approach to making the diagnosis.
- Tachycardia as a Red Flag: In pediatric emergency medicine, unexplained tachycardia should always raise concern. Children can compensate for shock longer than adults, maintaining a normal blood pressure even with significant cardiac compromise. A child with unexplained tachycardia who isn’t feverish, in pain, or dehydrated should be closely monitored for serious underlying conditions like myocarditis or sepsis.
Final Thoughts
Kawasaki Disease and myocarditis are two potentially life-threatening conditions that can present subtly in pediatric patients. Co-infections, incomplete presentations, and missed history are common pitfalls in diagnosing KD. Myocarditis can mimic benign viral illnesses, and no single test is reliable for diagnosis. Maintain a high level of suspicion for both conditions, use the AHA KD guidelines, and never ignore unexplained tachycardia.
Note: This post is based on a presentation given by Dr. Jeffrey Oestreicher at the Annual Pediatric Emergency Medicine Symposium held by Cohen Children’s Medical Center. For more information about attending future symposiums, please email Dr. Josh Rocker at jrocker@northwell.edu
Dr. Jeffrey Oestreicher, MD, is a Pediatric Emergency Medicine physician at Cohen Children’s Medical Center. He can be reached at joestreich@northwell.edu.
