MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN WITH COVID-19

How common is covid-19 in children?

 Since the outbreak of sars-cov-2 viral infection children are found to less susceptible to infection. Very few cases require ICU care. However, recently few cases with significant inflammatory findings resembling Kawasaki disease (KD) or KD shock have been reported.

What is multisystem inflammatory syndrome in children (MIS-C)?

 It is a rare condition in children with covis-19 presenting with features like Kawasaki disease. They have been found to have features of cytokine storm.

Also called

Pediatric multisystem inflammatory syndrome (PMIS)

Pediatric inflammatory multisystem syndrome (PIMS)

Pediatric hyperinflammatory syndrome or shock.

This KD like illness was first reported from United Kingdom in mid-April. There was a case series published from Italy as well. However, after that many cases have been reported from other European countries, USA (particularly New York) and Canada.

Although it is a rare presentation, pediatricians and parents should be aware of such condition which has a significant risk factor for mortality and morbidity.

How is MIS-C similar to Kawasaki disease?

 MIS-C fulfills most of the criteria of complete or incomplete Kawasaki disease.

How does it differ from Kawasaki disease?

KD is more common in infant and younger age groups whereas MIS-C is common in older and adolescent.

KD rarely present with KD shock syndrome whereas MIS-C usually present with shock.

The risk of coronary artery aneurysm is found to be higher in MIS-C compared to KD.

KD is common in East Asian children whereas MIS-C common black children.

What is the pathophysiology of MIS-C?

 Although the exact cause is not known, it is most probably a post-infectious condition characterized by cytokine storm.

The exaggerated and inappropriate immune response leads to multisystem inflammatory response.

CLICK HERE FOR DETAILS ON CYTOKINE STORM IN COVID-19

What are the most common symptoms at presentation?

Fever in 100%

Most of the children present with GI symptoms like abdominal pain, vomiting mimicking appendicitis.

Some with documented ileitis in imaging.

Respiratory symptoms, rash, conjunctivitis, neurocognitive symptoms like -headache, confusion, sore throat, swollen hands and feet can be present.

Most of the cases presented with fever for 4-5 days followed by warm shock.

Shock are often fluid refractory, requiring vasopressors and mechanical ventilation.

Respiratory involvement is not a prominent feature although many patients presented with tachypnea, labored breathing due to shock and required mechanical ventilation.

What are the common clinical findings?

 Shock in 60-80% cases

KD diagnostic criteria in 50 to 64%

Myocardial dysfunction

Acute respiratory failure in 52-68%

AKI

Serositis

Acute hepatic failure

What are the laboratory findings?

CBC-

Lymphocytopenia is characteristics

Neutrophilia, mild anemia and thrombocytopenia may occur.

Elevated Inflammatory markers

CRP

ESR

Procalcitonin

Ferritin

 

Elevated D-dimers, fibrinogen

Elevated cytokines like- IL-6

 

Elevated cardiac markers: Troponin and BNP or NT-pro-BNP

Hypoalbuminemia

Elevated liver enzymes

Elevated LDH

Hypertriglyceridemia.

IL-6 plays an important role in cytokine storm and if IL-6 measurement facility is available in labs it can act as early indicator of MIS-C. It starts rising within 3 hours of MIS-C as compared to 48-72 hours of serum ferritin.

 

What are the imaging findings?

Echocardiography- LV systolic dysfunction, Pericardial effusion, mitral and other valvular regurgitation and coronary artery abnormalities including dilatation.

CXR, CT chest – atelectasis, pleural effusion, consolidation

In CT nodular ground glass opacification may be present.

Abdominal USG/CT- free fluid, ascites and bowel and mesenteric inflammation

How does CDC (Center for disease control and Prevention) define MIS-C?

The CDC case definition

MIS-C is defined by meeting all of the following criteria:

·         An individual

aged <21 years presenting with fever*

evidence of inflammation#, and

evidence of clinically severe illness requiring hospitalization, with

multisystem (>2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological); AND

  • No alternative plausible diagnoses; AND

 

  • Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test; or COVID-19 exposure within the 4 weeks prior to the onset of symptoms

*Fever >38.0°C for ≥24 hours, or report of subjective fever lasting ≥24 hours


#Including, but not limited to, one or more of the following: an elevated C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fibrinogen, procalcitonin, d-dimer, ferritin, lactic acid dehydrogenase (LDH), or interleukin 6 (IL-6), elevated neutrophils, reduced lymphocytes and low albumin

Additional comments

  • Some individuals may fulfill full or partial criteria for Kawasaki disease but should be reported if they meet the case definition for MIS-C
  • Consider MIS-C in any pediatric death with evidence of SARS-CoV-2 infection.

What is the WHO case definition for MIS-C?

The case definition is children and adolescents aged 0–19 with fever for more than three days who have two of the following: 

  • Rash or bilateral non-purulent conjunctivitis or muco-cutaneous inflammation signs (oral, hands or feet)
  • Hypotension or shock
  • Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including ECHO findings or elevated Troponin/NT-proBNP)
  • Evidence of coagulopathy (by PT, PTT, elevated d-Dimers)
  • Acute gastrointestinal problems (diarrhea, vomiting, or abdominal pain)

AND

  • Elevated markers of inflammation such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), or procalcitonin 

AND

  • No other obvious microbial cause of inflammation, including bacterial sepsis, staphylococcal or streptococcal shock syndromes 

AND

  • Evidence of COVID-19 (RT-PCR, antigen test or serology positive), or likely contact with patients with COVID-19 

 

What are the spectrums of covid-19 disease in children?

 Covid-19 without exaggerated immune response- most cases with mild or no symptoms

Covid -19 with mild symptoms- persistent fever and mild symptoms with elevated ferritin

Covid-19 associated KD – Covid-19 patients fulfilling complete or incomplete criteria for KD but do not develop shock and multisystem disorder.

Covid-19 with MIS-C – multisystem involvement. Cardiac involvement and shock are common.

 

How do we proceed in a suspected case of covid-19 MIS-C?

In mild cases with persistent fever but only mild symptoms do CBC and CRP to follow up and to do additional tests as per requirement.

In moderate to severe cases

CBC, RFT, LFT, Serum electrolytes, CRP, ESR, Procalcitonin, Triglyceride, Ferritin, urinalysis, troponin, BNP, INR, APTT, D-dimer, Fibrinogen

If available cytokine panel.

Test for SARS-COV-2 by RT-PCR or Serology or Antigen panel

What do we expect in SARS-COV-2?

Since, it is a post infectious immune reaction serological test is likely to be positive rather than the PCR and in most of the cases this is what is observed.

Most of the cases are PCR negative and serology positive

Few cases are positive in PCR as well as serology

Few are only PCR positive

In very few cases both are negative.

Is it necessary to rule out other infections?

It is also important to rule out other causes so following investigations are to be done in moderate to severe cases:

Blood c/s, urine c/s, throat c/s, stool c/s, EBV PCR, CMV PCR, Adenovirus PCR.

Echocardiography is to be done and if abnormalities the most important being coronary artery aneurysm if present should be followed up.

 What are the differential diagnosis?

 Bacterial sepsis

Cardiac involvement like CA aneurysm is less common in bacterial sepsis

Microbiological testing can differentiate between MIS-C and bacterial sepsis

KD

Already discussed

Toxic shock syndrome

Microbiological testing is needed to differentiate

Appendicitis

Abdominal imaging is required

Other viral infections

Other viral infections like EBV, influenza, adeno, entero can also present with MIS-C.

HLH/MAS

Similar presentation with less cardiac and GIT manifestations with more neurological manifestations.

They are present in person with rheumatological illness

SLE with multisystem illness

Neurological and renal features are more common.

Most of the cases are known cases of SLE and they have been ill for extended duration of time unlike MIS-C children.

Vasculitis

Children with MIS-c also present with rash but the rash is not vasculitic rash.

 

Management

Multi-disciplinary approach

Moderate to severe cases should be admitted in PICU with proper monitoring

All cases treat as septic shock before microbiological diagnosis with proper antibiotics

PCR positive cases may be treated with Remdesivir or other anti-viral as per the treating physician.

Warm shock – fluid and in cases of fluid refractory start with EPINEPHRINE

In cases of significant myocardial dysfunction – milrinone may be helpful. Significant ventricular dysfunction must be treated with judicious use of diuretics, milrinone, dopamine and dobutamine. Although evidence is lacking some physician use IVIG for severe myocarditis with ventricular dysfunction

Fulminant myocardial dysfunction might require ECMO or Ventricular assist Device(VAD)

If child is meeting the criteria for KD --- IVIG, aspirin and in refractory cases treat as refractory KD

Kobayashi score can be applied and treat accordingly if suspicion of refractory KD in the first place.

What is the role of anti-thrombotic therapy?

 Start aspirin in all cases that meet the criteria for complete of incomplete KD. Other anticoagulants can be added in some cases depending upon the degree of CA dilation

All cases of significant myocardial dysfunction may be started on aspirin. However, this can be decided on case to case basis.

For children with MIS-C not fulfilling KD criteria but have moderate to severe disease the starting of antithrombotic should be individualized outweighing the risk of bleeding and other concomitant illness.

 What is the role of Immunomodulatory therapy?

This can be an area of debate. We can start steroids, IVIG, Anakinra or Tocilizumab with consultation of pediatric infectious disease expert. All these therapies are under investigation regarding their role in MIS-C. The starting of the therapy is clinician’s choice and may be started with the intent of conducting clinical trials.  

CLICK HERE FOR THERAPEUTIC IMPLICATIONS OF CYTOKINE STORM IN COVID-19 

As of mid-May 230 cases have been reported with at least 5 deaths.


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