dcyphr | An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study


In the past month, there was an outbreak of Kawasaki disease in the Bergamo province. Researchers compared past cases of Kawasaki disease before and after the SARS-CoV-2 pandemic.19 patients had Kawasaki disease from 2015 to Feb 17th 2020. There have been 10 cases of Kawasaki disease from Feb 18th to April 20th, 2020. The rate of Kawasaki disease incidence has increased by 30 times. A similar increased rate is expected in other countries affected by the SARS-CoV-2 outbreak.


Bergamo has had the highest rate of cases and deaths from SARS-CoV-2 in Italy. In adults, severe cases cause pneumonia and inflammation. Children usually don’t have severe respiratory complications. But, the cytokine storm caused by our own immune system can be very damaging to all age groups. Kawasaki disease is caused by inflammation to medium and large sized vessels in children. Some complications are Kawasaki disease shock syndrome (KDSS) and macrophage activation syndrome (MAS). The cause of this disease is unknown, but was thought to occur after an infection that would trigger the disease.


Past cases of Kawasaki disease were reviewed from records of Hospital Papa Giovanni XXIII in Bergamo, Italy. Diagnostic criteria of Kawasaki disease includes: fever for more than 5 days; with non liquidy eye redness; changes of lips and mouth; swollen lymph nodes; rash; reddening of the palms and feet; and thickening and hardening of the hands and feet. They also looked at low red blood cells count, high platelet count, low albumin, high liver enzymes, high white blood cell count, white blood cells in the urine, aortic aneurysm, or other cardiac dysfunction. KDSS occurs when there is a drop in blood pressure and the body cannot get enough oxygen. 

The hospital records showed the blood work, EKG results, and whether the patient had come into contact with a COVID-19 positive person. The patients and their caregivers were tested by nasal swab and RT-PCR for SARS-CoV-2. Some of the more recent patients were tested for IgG/IgM antibodies for COVID-19.

Patients were given aspirin, intravenous immunoglobulin, and methylprednisolone. This is the typical treatment for Kawasaki disease.


Group 2 consists of those who were diagnosed with Kawasaki disease from Feb 18th to April 20th, 2020. Group 2 has ten members between ages 2 and 16. 5 of the children had complete Kawasaki disease, meaning they had more of the symptoms. 5 of them had incomplete Kawasaki disease. Various patients met different criteria of the disease at different severities. 8 out of the 10 patients tested positive for SARS-CoV-2 or COVID-19 through nasal swab, RT-PCR, or IgG/IgM antibody tests.

Group 1 consists of patients who were diagnosed with Kawasaki disease before the COVID-19 outbreak. There were 19 patients diagnosed since Jan 1, 2015. On average, there are 0.3 patients diagnosed a month in Group 1. But Group 2 showed an incidence of 10 per month. The average age of Group 1 diagnosis was 3 years, but the average age of Group 2 diagnosis was 7.5 years. Group 2 had lower white blood cell and platelet counts than Group 1. In addition, Group 2 had more severe effects of Kawasaki disease than Group 1. 60% of Group 2 has irregular heart rhythms, but only 10% of Group 1 saw this complication. Steroid treatment was required for 80% of Group 2, but only for 16% of Group 1.


The first cases of Kawasaki disease have been documented over 50 years ago, but there is still no known cause. The main possible cause is a rare immune response to some type of disease. Previous studies have been done to identify other coronaviruses as the cause of Kawasaki disease as early as 2005 in New Haven, CT. But these studies have shown mixed results compared to Japanese studies, which is where Kawasaki disease was first identified.

Since the COVID-19 related outbreak of Kawasaki disease has more severe and slightly different presentations, the researchers have decided to call this “Kawasaki like disease.” Compared to Group 1 Kawasaki disease patients, Group 2 Kawasaki-like disease patients is they were older and had lung issues, digestive issues, and heart issues. The kawasaki-like disease is overall a more severe disease, so the patients were given steroids.

Since Kawasaki disease occurs weeks after the initial infection, this may explain why no trigger has been linked directly to the disease. Testing for IgG/IgM antibodies is a better way to look for triggers of Kawasaki and Kawasaki-like diseases than RT-PCR and the nasal swab.

This study recommends physicians to consider steroid treatment for Kawasaki-like disease patients with a positive SARS-CoV-2 IgG/IgM antibody test or another positive COVID-19 test.