Kawasaki disease for the paediatric dermatologist: skin manifestations and new insights into the pathophysiology

Kawasaki Disease

Kawasaki disease (KD) is an acute febrile, systemic vasculitis with an unknown etiology that mostly affects children under the age of 5, and it is the most common cause of acquired heart disease in children in developed countries. Despite significant advances in understanding this disease's pathophysiology, diagnostic methods, and treatment options, many aspects remain unclear, so this study aims to provide a comprehensive review of the current knowledge on KD. We reviewed the most recent research (2019-2024) to compile recent advances in the pathogenesis, immunologic mechanisms, clinical manifestations, and treatment of KD, while comparing it with the multisystem inflammatory syndrome in children. KD is associated with elevated inflammatory cytokines, autoantibodies, and endothelial dysfunction, leading to coronary artery lesions. Clinical diagnosis remains challenging and is based on laboratory markers, echocardiography, and differential diagnosis. Intravenous immunoglobulin and high-dose aspirin remain standard treatments, with immunomodulatory therapies for resistant cases. Multisystem inflammatory syndrome in children shares overlapping features but differs in age distribution, systemic involvement, and immune response. Given the critical importance of early diagnosis and management of KD in preventing coronary artery aneurysms, ongoing research is focused on elucidating the underlying mechanisms of the disease and developing novel therapeutic strategies. These efforts aim to enhance patient outcomes and reduce long-term cardiovascular risks.

Psoriasiform Dermatitis Following Kawasaki Disease: A Case Report and Literature Review

Kawasaki disease (KD) is an idiopathic acute inflammatory illness that commonly affects children in Northeast Asian countries. In this case report, a psoriasiform eruption appeared on the face and extremities following the onset of KD. A review of previous reports identified 38 cases of psoriasiform eruptions following KD, typically appearing 4 days to 2 months after the onset of KD, unlike other skin manifestations associated with the disease. Notably, in this case, the rash improved with the application of white petrolatum, suggesting that psoriasiform eruptions following KD may be self-limited with spontaneous resolution.

Precision Medicine in Congenital Heart Disease, Rheumatic Heart Disease, and Kawasaki Disease of Children: An Overview of Literature

Congenital heart disease and common acquired heart diseases like Kawasaki disease and rheumatic heart disease are prevalent cardiovascular conditions in children worldwide. Despite the availability of treatment options, they continue to be significant contributors to morbidity and mortality. Advancements in early diagnosis, improvements in treatment approaches, and overcoming resistance to available treatments are crucial to reduce morbidity. Researchers have turned to precision medicine to tackle these challenges. We aimed to analyze the existing literature concerning the utilization of precision medicine in congenital heart disease, rheumatic heart disease, and Kawasaki disease. The emphasis is placed on comprehending the key themes explored in these studies and evaluating the present state of their clinical integration. The central theme of most studies revolves around the examination of genetic factors. Despite promising research outcomes, limitations in these studies indicate that the clinical implementation of precision medicine in these conditions remains a distant prospect, necessitating additional exploration and attention to confounding factors.

Amino acids analysis reveals serum methionine contributes to diagnosis of the Kawasaki disease in mice and children

BACKGROUND

Kawasaki disease (KD) patients often lack early and definitive diagnosis due to insufficient clinical criteria, whereas biomarkers might accelerate the diagnostic process and treatment.

METHODS

The KD mouse models were established and thirteen amino acids were determined. A total of 551 serum samples were collected including KD patients (n = 134), HCs (n = 223) and KD patients after intravascular immunoglobulin therapy (IVIG, n = 194). A paired analysis of pre- and post-IVIG was employed in 10 KD patients.

RESULTS

The pathological alterations of the aorta, myocardial interstitium and coronary artery vessel were observed in KD mice; the serum levels of methionine in KD mice (n = 40) were markedly altered and negatively correlated with the C-reactive protein levels. Consistent with the mouse model, serum methionine were significantly decreased in KD children, with the relative variation ratio of KD with HCs above 30% and AUROC value of 0.845. Serum methionine were correlated with Z-Score and significantly restored to the normal ranges after KD patient IVIG treatment. Another case-control study with 10 KD patients with IVIG sensitivity and 20 healthy controls validated serum methionine as a biomarker for KD patients with AUROC of 0.86. Elevation of serum DNMT1 activities, but no differences of DNMT3a and DNMT3b, were observed in KD patients when comparing with those in the HCs.

CONCLUSIONS

Our study validated that serum methionine was a potential biomarker for KD, the alteration of which is associated with the activation of DNMT1 in KD patients.

Microvascular changes on nailfold capillaroscopy in acute stage of Kawasaki disease: a new diagnostic paradigm for an enigmatic condition

OBJECTIVES

Kawasaki disease (KD) is a medium vessel vasculitis with a predilection to involve coronary arteries. However, there is a paucity of literature on microvascular changes in patients with KD.

METHODS

Children diagnosed with KD based on American Heart Association guidelines 2017 were enrolled prospectively. Demographic details and echocardiographic changes in coronaries were recorded. Nailfold capillaries were assessed using Optilia Video capillaroscopy and data were analysed using Optilia Optiflix Capillaroscopy software at acute (prior to IVIG administration) and subacute/convalescent phase.

RESULTS

We enrolled 32 children with KD (17 boys) with a median age of 3 years. Nailfold capillaroscopy (NFC) was performed in 32 patients in the acute phase (compared with 32 controls) and in 17 during the subacute/convalescent phase at a median follow-up of 15 (15-90) days after IVIG treatment. The following findings were seen in NFC in the acute phase of KD: reduced capillary density (n = 12, 38.6%), dilated capillaries (n = 3, 9.3%), ramifications (n = 3, 9.3%) and capillary haemorrhages (n = 2, 6.2%). Capillary density was reduced significantly in the acute phase of KD (38.6%) as compared with the subacute/convalescent phase (25.4%) (P-value <0.001) and controls (0%) (P-value = 0.03). We observed no correlation between coronary artery involvement and mean capillary density (P = 0.870).

CONCLUSION

Results show that patients with KD have significant nailfold capillary changes in the acute phase. These findings may provide a new diagnostic paradigm for KD and a window to predict coronary artery abnormalities.

The many faces of pediatric urticaria

Urticaria is a common disease that can affect individuals of all age groups, with approximately one-quarter of the population experiencing it at least once in their lifetime. Lesions characterized by erythema and itchy hives can appear anywhere on the body. These can vary in size ranging from millimeters to centimeters, and typically clear within 24 h. About 40% of patients with urticaria have accompanying angioedema, which involves localized deep tissue swelling. Urticaria usually occurs spontaneously and is classified into acute and chronic forms, with the latter referring to a condition that lasts for more than 6 weeks. The prevalence of chronic urticaria in the general population ranges from 0.5% to 5%, and it can either be inducible or spontaneous. The most common form of pediatric urticaria is acute and is usually self-limiting. However, a broad differential diagnosis should be considered in children with urticaria, particularly if they also have accompanying systemic complaints. Differential diagnoses of pediatric urticaria include chronic spontaneous urticaria, chronic inducible urticaria, serum sickness-like reaction, urticarial vasculitis, and mast cell disorders. Conditions that can mimic urticaria, including but not limited to cryopyrinopathies, hyper IgD syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis (PFAPA), Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPs), and Schnitzler syndrome should also be considered. The many faces of pediatric urticaria can be both easy and confusing. A pragmatic approach relies on clinical foresight and understanding the various forms of urticaria and their potential mimickers. This approach can pave the way for an accurate and optimized diagnostic approach in children with urticaria.

French national diagnostic and care protocol for Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis with a particular tropism for the coronary arteries. KD mainly affects male children between 6 months and 5 years of age. The diagnosis is clinical, based on the international American Heart Association criteria. It should be systematically considered in children with a fever, either of 5 days or more, or of 3 days if all other criteria are present. It is important to note that most children present with marked irritability and may have digestive signs. Although the biological inflammatory response is not specific, it is of great value for the diagnosis. Because of the difficulty of recognising incomplete or atypical forms of KD, and the need for urgent treatment, the child should be referred to a paediatric hospital as soon as the diagnosis is suspected. In the event of signs of heart failure (pallor, tachycardia, polypnea, sweating, hepatomegaly, unstable blood pressure), medical transfer to an intensive care unit (ICU) is essential. The standard treatment is an infusion of IVIG combined with aspirin (before 10 days of fever, and for a minimum of 6 weeks), which reduces the risk of coronary aneurysms. In case of coronary involvement, antiplatelet therapy can be maintained for life. In case of a giant aneurysm, anticoagulant treatment is added to the antiplatelet agent. The prognosis of KD is generally good and most children recover without sequelae. The prognosis in children with initial coronary involvement depends on the progression of the cardiac anomalies, which are monitored during careful specialised cardiological follow-up.

New dermatological findings of MIS-C: Can mucocutaneous involvement be associated with Severe Disease Course?

BACKGROUND

Little is known about mucocutaneous involvement in critically ill patients with the multisystem inflammatory syndrome in children (MIS-C). The aim of our study was to describe the localisation and variety of rash and to investigate whether presenting with rash at admission alters the clinical course of MIS-C.

METHODS

This prospective, observational cohort study was conducted amongst children under 18 years of age who were admitted to our paediatric intensive care unit (PICU) between May 2020 and May 2021 with a possible diagnosis of MIS-C.

RESULTS

A total of 33 children with MIS-C, 21 boys (64%), with a median age of 9.4 years (3.4-11.5) were enrolled. Twenty-four children presented with mucocutaneous symptoms (72%). Age, male gender, PICU length of stay, presenting symptoms, inotrope requirement, the existence of myocarditis or respiratory failure were higher but not significantly different in patients with rash compared to those without rash (P > 0.05). The median duration of symptoms before admission and presence of cervical lymphadenopathy were significantly higher in patients than those without rash (P < 0.05). Children with a rash had a significantly higher neutrophil count, CRP, procalcitonin, troponin levels and lower lymphocyte counts and albumin levels than those without rash (P < 0.05). Twelve children with rash (50%) had symmetrical intertriginous distribution. Two children had erythematous lesions on the areola and the surroundings. In conclusion, intertriginous involvement, periareolar erythema and other mucocutaneous manifestations might be the first alarming symptoms of moderate to severe MIS-C. Therefore, close monitoring with a multidisciplinary approach should be considered for these patients to assess potential disease progression.