Kawasaki Disease
Introduction
Kawasaki disease (ka-wuh-sa-kee) is a disease that is caused by inflammation of many different blood vessels all over the body. It usually affects children under 5 years old. It is diagnosed based on the symptoms and signs that a child presents with, as there is no specific test for this disease. It is important to detect and treat it properly and if left untreated, it can cause heart problems later in life. There are about 200-300 cases of KD diagnosed each year in Australia.
Who gets it?
Of all cases of KD, 8 out of 10 cases occur in children less than 5 years old, with the majority being 1 and 2 years old.
KD is more common in boys than girls.
KD is very uncommon in people over 14 years old and children under six months old.
KD is most common in children of Asian descent, especially Japanese descent.
What causes it?
The cause of KD is not known. The disease is caused by an inflammation of blood vessels inside the body and this is probably triggered by an infection, although we do not know what type of infection. Current research suggests that some genes may make you more likely to get KD. Although it is thought that KD may be caused by an infection, it is not considered a contagious disease.
What does it look and feel like?
Looks like…
The rash in KD can be different in different children. It can look like red blotches, bumps, welts, pimples, or ‘target’ shapes.
The rash is usually more obvious in the nappy area.
Your child may have a sore, red mouth or a red lumpy “strawberry” tongue.
Your child may have red or cracked lips.
Your child may have lumps in the neck which are due to swollen glands.
The eyes can become red and sore.
The hands and feet can become swollen and red and the skin may peel.
Feels like…
Children with KD are often very irritable.
Your child may have high fevers (over 39°C).
Your child’s heartbeat may run fast or in an abnormal rhythm.
Your child may have other symptoms such as tummy pain, diarrhoea, pain passing urine, joint pain or swelling, headaches, neck stiffness, chest pain, shortness of breath or cough.
What tests might be needed?
Diagnosis is based on a whether the fever has lasted at least five days, and by the other symptoms as well as the physical exam. If your doctor thinks your child might have KD, they will arrange a blood test, a urine test, and an ultrasound of the heart. Other tests can also be done to rule out diseases which can cause similar symptoms to KD, such as a nasal swab to rule out COVID-19 and other respiratory viruses.
What treatments are available?
What can I do?
Seek urgent medical attention as prompt treatment can prevent complications of KD.
Paracetamol (Panadol) may help with fever and irritability.
Your child may not want to eat as much as usual, so make sure they are well-hydrated by giving them small frequent sips of fluid (preferably water), jelly, icy-poles, and soup.
Medical therapies
Treatment is most effective when started in the first 10 days of the illness. The main treatment is immunoglobulin (or IVIG) which is made from the antibody collected from blood donations. This is a very safe treatment and dramatically reduces the risk of a child with KD having serious heart problems. IVIG is usually given through a vein over several hours and most children will feel better within 24 hours. Aspirin is usually also given in order to reduce the risk of blood clots in the arteries of the heart.
If the signs and symptoms do not resolve, or recur within a few days, a second dose of IVIG may be given. In some children, IVIG may not work well and oral steroids may be given.
What happens after treatment?
The inflammation caused by Kawasaki disease can affect a child’s heart. The risk of heart complications due to Kawasaki disease can be greatly reduced by early treatment.
With treatment, children tend to improve quickly with the signs and symptoms resolving in 1-2 days. The long-term recovery from KD depends on how much the heart is affected and how soon after symptoms the treatment was started. After being discharged from hospital:
Monitor for fever for 48 hours after discharge home from hospital.
Cardiac evaluations: a baseline ultrasound of the heart is usually done at diagnosis, but a repeat ultrasound will be done after 2 to 6 weeks. Children with significant heart complications should be followed by a long-term cardiologist.
Vaccinations: If your child gets IVIG treatment, they may not be able to get certain vaccines for at least a year because the vaccines may not work as well.
What support is available?
Your GP, paediatrician, dermatologist, and cardiologist can work together to look after your child with KD.
Kawasaki Disease Foundation Australia is an organisation for families affected by KD. https://kdfoundation.org.au
Authors/Reviewers:
Author: Dr Sarah Hanna
Paediatric Reviewer: Dr Mayuri Sivagnanam
Editor in Chief: Dr Tevi Wain