# Kawasaki Disease in a Child With Trisomy 18 Treated With Initial Combination Therapy, Including Cyclosporine

## TL;DR

A child with trisomy 18 and Kawasaki disease was successfully treated with a combination therapy including cyclosporine, showing a favorable outcome.

## Contribution

This is the first reported case of Kawasaki disease in a child with trisomy 18 treated with cyclosporine as part of initial therapy.

## Key findings

- The patient met five of six diagnostic criteria for Kawasaki disease and showed defervescence without complications.
- No coronary artery abnormalities were observed during or after treatment.
- The treatment regimen including cyclosporine was safely administered with no adverse events.

## Abstract

Kawasaki disease is a systemic inflammatory disorder that is frequently encountered in routine pediatric clinical practice. Conversely, trisomy 18 is a chromosomal disorder with a historically poor prognosis. However, recent advances in medical care have improved its survival, with a reported 1‐year survival rate reaching 29%. Despite this improvement, studies describing the clinical course of individuals with trisomy 18 beyond the first year of life remain scarce. Moreover, to our knowledge, cases of Kawasaki disease with trisomy 18 have not been reported.

We report a case of a 3‐year‐11‐month‐old girl with trisomy 18 who presented with persistent fever and rash and, subsequently, fulfilled five of the six principal diagnostic criteria for Kawasaki disease. Because intravenous immunoglobulin resistance was predicted based on the Kobayashi score, initial treatment consisted of intravenous immunoglobulin (2 g/kg), aspirin, and oral cyclosporine concurrent with current Japanese guidelines. Defervescence was achieved without complications, and no adverse events were observed during treatment. No coronary artery abnormalities were observed during the acute phase or at 1‐, 3‐, and 6‐month follow‐up evaluations.

We present a case of trisomy 18 treated according to Japanese guidelines for Kawasaki disease. Treatment regimen, which included cyclosporine, was safely administered, and the patient experienced a favorable clinical course. To improve the life expectancy of this patient group, it is crucial to accumulate comprehensive natural history, including the efficacy of standard treatments for various pediatric conditions. This will enable timely and appropriate therapeutic interventions.