Cervical ultrasound and computed tomography of Kawasaki disease: Comparison with lymphadenitis

Parapharyngeal and retropharyngeal infections in children: Kawasaki disease needs vigilance

OBJECTIVE

Kawasaki Disease (KD) may mimic Parapharyngeal (PPI) and Retropharyngeal Infections (RPI), leading to misdiagnosis as Deep Neck Infections (DNIs). The treatment plans for the two diseases are different, and delayed treatment can lead to serious complications. Therefore, prompt diagnosis and management are necessary. This study was performed to evaluate the clinical features of KD mimicking DNIs and explore the treatment options.

METHODS

Children with cellulitis or abscess in parapharyngeal or retropharyngeal space in neck CT were included in this study. The medical records of enrolled children were retrospectively reviewed.

RESULTS

In total, 56 children were diagnosed with PPI or/and RPI. Twenty-two (39.3%) participants were eventually diagnosed with KD, and 34 (60.7%) were diagnosed with DNIs. Compared with the DNIs group, the KD group had a higher body temperature (p=0.007), and higher levels of AST (p=0.040), ALT (p=0.027), and ESR (p=0.030). Deep cervical cellulitis (p=0.005) were more common in the KD group. However, deep neck abscess often occurred in the DNIs group (p=0.002), with parapharyngeal abscess being the most common type of abscess (p=0.004). The KD mimicking DNIs cases did not respond to antibiotic treatment, but symptoms significantly improved after the use of Immunoglobulin (IVIG) and aspirin.

CONCLUSION

Children with KD may exhibit retropharyngeal or parapharyngeal inflammation in the early stages. KD should be considered a differential diagnosis for children with DNIs, high fever, and no response to antibiotic therapy. Surgery in KD mimicking deep neck abscess requires caution.

LEVEL OF EVIDENCE

I.

Evaluating Lymph Node Stiffness to Differentiate Bacterial Cervical Lymphadenitis and Lymph Node-First Presentation of Kawasaki Disease by Shear Wave Elastography

OBJECTIVES

The purpose of our study was to evaluate the potential of cervical lymph node shear wave elastography (SWE) to quantify the lymph node stiffness (kilopascals) noninvasively among patients with lymph node-first presentation of Kawasaki disease (NFKD), patients with bacterial cervical lymphadenitis (BCL), and healthy children (HC). We further aimed to investigate the correlation of laboratory data and lymph node stiffness to provide a reference basis for the early diagnosis of NFKD.

METHODS

Lymph node stiffness measurements were prospectively performed in 47 patients with NFKD, 56 patients with BCL, and 56 HC using SWE. Cervical SWE was compared in the groups. Factors associated with increased cervical lymph node stiffness were studied.

RESULTS

The mean elasticity of the largest cervical lymph nodes was significantly higher in the BCL group than the NFKD and HC groups (mean elasticity ± SD, 16.37 ± 2.45, 12.22 ± 2.64, and 7.81 ± 1.67 kPa, respectively; P < .01), with a cutoff of 14.55 kPa (area under the curve, 0.885; sensitivity, 89%; and specificity, 76%). In patients with NFKD, interleukin 6 (standardized β = 0.363; P = .01), alanine aminotransferase (standardized β = 0.253; P = .03), aspartate aminotransaminase (standardized β = 0.536; P = .047), and total bilirubin (standardized β = 0.486; P < .01) values were correlated with increased largest cervical lymph node stiffness.

CONCLUSIONS

Cervical lymph node stiffness was different between NFKD and BCL. Shear wave elastography is a potential method to identify clinically distinguishable early NFKD.

A febrile child with a 'bunch of grapes' appearance on neck ultrasonography

Kawasaki disease is a common childhood vasculitis. Fever and lymphadenopathy, at times, are the only clinical presentation of Kawasaki disease, which mimics infectious lymphadenitis, especially, when other features are yet to evolve. In such a scenario, ultrasonography of cervical lymph nodes can help to differentiate Kawasaki disease lymphadenitis from infectious lymphadenitis. We present one such patient who was initially diagnosed as having bacterial lymphadenitis; however, ultrasonography of the neck lymph nodes showed typical imaging features described with Kawasaki disease lymphadenitis.

Prediction Model for the Differential Diagnosis of Kawasaki Disease and Acute Cervical Lymphadenitis in Patients Initially Presenting with Fever and Cervical Lymphadenitis

OBJECTIVES

To distinguish early-stage lymph node first presentation of Kawasaki disease from acute cervical lymphadenitis, we developed an algorithm using sequential laboratory marker levels and radiologic findings.

STUDY DESIGN

Data were obtained from pediatric inpatients initially presenting with fever and cervical lymphadenopathy. Discriminative factors for the differential diagnosis of acute cervical lymphadenitis and lymph node first presentation of Kawasaki disease were identified from intergroup comparison or univariate logistic regression analysis. A model for differentiating between lymph node first presentation of Kawasaki disease and acute cervical lymphadenitis was constructed using decision-tree analysis.

RESULTS

Patients were divided into 2 cohorts: training (206 patients) and validation (103 patients) cohorts. A decision-tree model developed from the data of the training cohort included 3 determinants: neck computed tomography- or ultrasonography-defined abscess, percentage change in C-reactive protein level, and percentage change in neutrophil count. The prediction power of our decision-tree model for the validation cohort was superior to that of previously known laboratory markers (sensitivity of 89.5%, specificity of 88.9%, positive predictive value of 95.8%, negative predictive value of 75.0%, overall accuracy of 89.3%, and a Youden index of 0.784).

CONCLUSIONS

A decision-tree model could differentiate lymph node first presentation of Kawasaki disease from acute cervical lymphadenitis with an increased accuracy. External validation based on multicenter data is needed before clinical application.

Kawasaki Disease and COVID-19

The recent passing away of Dr. Tomisaku Kawasaki, who first described what is now known as Kawasaki Disease (KD), and recent reports of a multisystem inflammatory disease in children associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (MIS-C), makes a review on KD and MIS-C timely. Kawasaki Disease is a systemic vasculitis with predilection for coronary arteries occurring mostly in early childhood. The main features are high fever, extensive skin rash, cheilitis with red, cracking, bleeding lips and strawberry tongue, conjunctivitis, erythema and induration of hands and feet, subsiding with periungual peeling, cervical lymphadenopathy, and coronary artery dilation/aneurysms. Treatment consists of intravenous (IV) immunoglobulin (Ig) plus acetylsalicylic acid. MIS-C is considered a cytokine storm with high fever, inflammation, multi-organ dysfunction, that shares features with KD, toxic shock, and macrophage activation syndrome. Many children require admission to paediatric intensive care units for circulatory support. Bacterial sepsis, staphylococcal toxic shock syndrome, and enterovirus-causing myocarditis should be excluded. Treatment is not standardized and includes IVIg, IV methylprednisolone and IL-6 and IL-1 inhibitors.

Cervical lymphadenopathy in children: a diagnostic tree analysis model based on ultrasonographic and clinical findings

OBJECTIVES

To establish a diagnostic tree analysis (DTA) model based on ultrasonography (US) findings and clinical characteristics for differential diagnosis of common causes of cervical lymphadenopathy in children.

METHODS

A total of 242 patients (131 boys, 111 girls; mean age, 11.2 ± 0.3 years; range, 1 month-18 years) with pathologically confirmed Kikuchi disease (n = 127), reactive hyperplasia (n = 64), lymphoma (n = 24), or suppurative lymphadenitis (n = 27) who underwent neck US were included. US images were retrospectively reviewed to assess lymph node (LN) characteristics, and clinical information was collected from patient records. DTA models were created using a classification and regression tree algorithm on the basis of US imaging and clinical findings. The patients were randomly divided into training (70%, 170/242) and validation (30%, 72/242) datasets to assess the diagnostic performance of the DTA models.

RESULTS

In the DTA model based on all predictors, perinodal fat hyperechogenicity, LN echogenicity, and short diameter of the largest LN were significant predictors for differential diagnosis of cervical lymphadenopathy (overall accuracy, 85.3% and 83.3% in the training and validation datasets). In the model based on categorical parameters alone, perinodal fat hyperechogenicity, LN echogenicity, and loss of fatty hilum were significant predictors (overall accuracy, 84.7% and 86.1% in the training and validation datasets).

CONCLUSIONS

Perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum were significant US findings in the DTA for differential diagnosis of cervical lymphadenopathy in children.

KEY POINTS

• Diagnostic tree analysis model based on ultrasonography and clinical findings would be helpful in differential diagnosis of pediatric cervical lymphadenopathy. • Significant predictors were perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum.

Kawasaki disease with retropharyngeal edema: case series from a single center experience

Supplemental Digital Content is available in the text

Deep Neck Inflammation: Probable Kawasaki Disease in Korean Children

Objectives

Deep neck infections (DNIs) can cause life-threatening complications, and prompt diagnosis and management are necessary. Kawasaki disease (KD) may be accompanied by deep neck inflammation; making it difficult to distinguish from DNIs. This study was performed to evaluate clinical features and outcomes of children with parapharyngeal and retropharyngeal inflammation.

Methods

Medical records of the children diagnosed with parapharyngeal and retropharyngeal cellulitis or abscess using cervical computed tomography (CT) between 2013 and 2017 were retrospectively reviewed.

Results

A total of 47 children were diagnosed with parapharyngeal and retropharyngeal inflammation. Eleven (23.4%) of them were eventually diagnosed with KD, and 36 (76.6%) were diagnosed with DNIs. There were no significantly different clinical and laboratory characteristics on admission between children diagnosed with KD and DNIs; however, significantly more children with KD were febrile for ≥3 days after admission compared to those with DNIs (P=0.009). Deep neck abscesses on CT were observed in 16 children with DNIs (44.4%) and in no child with KD (P=0.009). Among the 36 children with DNIs, 30 (83.3%) were cured with antibiotic therapy only.

Conclusion

A quarter of children presenting with deep neck inflammation were diagnosed with KD. KD should be considered in children showing deep neck inflammation unresponsive to empirical antibiotic therapy after 3 days, especially in those presenting with deep neck cellulitis rather than deep neck abscess.

A Case of Incomplete and Atypical Kawasaki Disease Presenting with Retropharyngeal Involvement

Background: Kawasaki disease (KD) is a childhood acute febrile vasculitis of unknown aetiology. The diagnosis is based on clinical criteria, including unilateral cervical lymphadenopathy, which is the only presenting symptom associated with fever in 12% of cases. A prompt differential diagnosis distinguishing KD from infective lymphadenitis is therefore necessary to avoid incorrect and delayed diagnosis and the risk of cardiovascular sequelae. Case presentation: We describe the case of a 4 years old boy presenting with febrile right cervical lymphadenopathy, in which the unresponsiveness to broad-spectrum antibiotics, the following onset of other characteristic clinical features and the evidence on the magnetic resonance imaging (MRI) of retropharyngeal inflammation led to the diagnosis of incomplete and atypical KD. On day 8 of hospitalisation (i.e., 13 days after the onset of symptoms), one dose of intravenous immunoglobulins (IVIG; 2 g/kg) was administered with rapid defervescence, and acetylsalicylic acid (4 mg/kg/day) was started and continued at home for a total of 8 weeks. Laboratory examinations revealed a reduction in the white blood cell count and the levels of inflammatory markers, thrombocytosis, and persistently negative echocardiography. Clinically, we observed a gradual reduction of the right-side neck swelling. Fifteen days after discharge, the MRI of the neck showed a regression of the laterocervical lymphadenopathy and a resolution of the infiltration of the parapharyngeal and retropharyngeal spaces. Conclusion: Head and neck manifestations can be early presentations of KD, which is frequently misdiagnosed as suppurative lymphadenitis or retropharyngeal infection. A growing awareness of the several possible presentations of KD is therefore necessary. Computed tomography (CT) or MRI can be utilised to facilitate the diagnosis.

Differentiation of Kawasaki Disease From Other Causes of Fever and Cervical Lymphadenopathy: A Diagnostic Scoring System Using Contrast-Enhanced CT

OBJECTIVE

The purpose of this study is to determine the characteristic findings of contrast-enhanced CT (CECT) of the neck in patients with Kawasaki disease (KD) and to develop a diagnostic scoring system to facilitate the diagnosis of KD versus other causes of fever and cervical lymphadenopathy.

MATERIALS AND METHODS

Two blinded radiologists evaluated CECT images of 37 patients with KD and 92 patients without KD who had febrile cervical lymphadenopathy, first independently and then in consensus. Significant findings in CECT images were evaluated through cervical edema and lymph node scores. CT attenuation of the nodal low-attenuation area and its ratio to the CT attenuation of the trapezius muscle were measured. On the basis of these indexes, a diagnostic scoring system was developed to differentiate between patients with and without KD. Its diagnostic performance was determined using ROC curve analysis.

RESULTS

Retropharyngeal edema, lateral cervical edema, nasopharyngeal wall edema, level IIA lymphadenopathy, and retropharyngeal lymphadenopathy were more common in patients with KD than in patients without KD (p < 0.001, < 0.001, < 0.001, 0.003, and 0.028, respectively). Level VB lymphadenopathy was more common in patients without KD (p = 0.013), and the presence of nodal low-attenuation areas with lower attenuation indexes (attenuation of nodal low-attenuation area ≤ 50 HU, or ratio of attenuation of nodal low-attenuation area to trapezius muscle attenuation ≤ 0.7) was specific to patients without KD. In cases of higher attenuation indexes and cervical edema and lymph node scores of 4 or higher, sensitivity, specificity, and accuracy of the diagnostic scoring system were 86% (32/37), 86% (79/92), and 86% (111/129), respectively, for diagnosing KD.

CONCLUSION

The proposed diagnostic scoring system was useful in differentiating between patients with and without KD.

Imaging and Clinical Data Distinguish Lymphadenopathy-First-Presenting Kawasaki Disease from Bacterial Cervical Lymphadenitis

BACKGROUND

Kawasaki disease (KD) sometimes presents with only fever and cervical lymphadenopathy before other clinical signs materialize. This lymphadenopathy-first-presenting Kawasaki disease (LKD) may be misdiagnosed as bacterial cervical lymphadenitis (BCL). We investigated characteristic imaging and clinical data for factors differentiating LKD from BCL.

METHODS

We compared imaging, clinical, and laboratory data of patients with KD and BCL. We included patients admitted to a single tertiary center between January 2015 and July 2018.

RESULTS

We evaluated data from 51 patients with LKD, 63 with BCL, and 218 with typical KD. Ultrasound imaging revealed multiple enlarged lymph nodes in both LKD and BCL patients. On the other hand, computed tomography (CT) showed more abscesses in patients with BCL. Patients with LKD were younger and showed higher systemic and hepatobiliary inflammatory markers and pyuria than BCL patients. In multivariable logistic regression, younger age and higher C-reactive protein (CRP) retained independent associations with LKD. A comparison of the echocardiographic findings in LKD and typical KD showed that patients with LKD did not have a higher incidence of coronary artery abnormalities (CAA).

CONCLUSIONS

LKD patients tend to have no abscesses on CT and more elevated systemic hepatobiliary inflammatory markers and pyuria compared to BCL patients. The absence of abscess on CT, younger age, and elevated CRP were the most significant variables differentiating LKD from BCL. There was no difference in CAA between LKD and typical KD.

Diagnosis of Kawasaki disease

Kawasaki disease (KD) is a medium vessel vasculitis with predilection for coronary arteries. Due to lack of a reliable confirmatory laboratory test, the diagnosis of KD is based on a constellation of clinical findings that appear in a typical temporal sequence. These diagnostic criteria have been modified from time to time and the most recent guidelines have been proposed by the American Heart Association (AHA) in 2017. However, several children may have incomplete or atypical forms of KD and the diagnosis can often be difficult, especially in infants and young children. In this review, we have detailed the steps involved in arriving at a diagnosis of KD and also highlight the important role of echocardiography in diagnosis and management of children with KD.

Adult Recurrence of Kawasaki Disease Mimicking Retropharyngeal Abscess

Kawasaki disease (KD) is an acute, self-limited vasculitis of unknown etiology that occurs predominantly in young children (≤5 years of age). We herein report the case of an 18-year-old Japanese man with a history of incomplete KD during infancy; later, despite an initial diagnosis of retropharyngeal abscess, he was ultimately diagnosed with retropharyngeal edema associated with recurrent KD. Adult-onset or recurrent KD is an uncommon event, and retropharyngeal edema is a rare manifestation of this disease. Internists should be aware of the possibility of KD that mimics a retropharyngeal abscess, even in adult patients.