The excat pathophysiological mechanism of MIS-C is unclear. Since there is a lag time between MIS-C appearance and COVID-19 infection it is suspected to be causing by antibody dependent enhancement.[3]
Another hypothesis is that since coronavirus block type1 and type III interferons, it results in delayed cytokine response in children with initially high viral load or whose immune response is unable to control infections causing MIS-C. Therefore, IFN responses result in viral clearance when the viral load is low resulting in mild infection. However, when the viral load is high and /or immune system is not able to clear the virus, the cytokine storm result in multisystem inflammatory syndrome in children (MIS-C).[3]
It is also suspected that since MIS-C presents predominantly with gastrointestinal manifestations, it replicates predominantly in the gastrointestinal tract.[3]
Differentiating Any Disease from other disease[edit | edit source]
It should be differentiated from following diseases
Bacterial sepsis
Staphylococcal and streptococcal toxic shock syndrome
Kawasaki disease.
More information about the differential diagnosis could be found here.
According to a recent study among the 186 children with MIS-C, the rate of hospitalization was 12% between March 16 and April 15 and 88% between April 16 and May 20.
80% of the children were admitted to the intensive care unit and 20% of the children required mechanical ventilation.[4]
4% of the children required extracorporeal membrane oxygenation.[4]
The mortality rate among 186 children with MIS-C was 2%.[4]
Age
Among the 186 children with MIS-C distribution of age group was[4]
<1yr-7%
1-4yr-28%
5-9yr-25%
10-14yr-24%
15-20yr-16%.
Gender
Among the 186 children with MIS-C
Comorbidities
Children with MIS-C had following underlying comorbidities.[4]
Clinically diagnosed Obesity-8%
BMI-Based Obesity-29%
Cardiovascular diasease-3%
Respiratory disease-18%
Autoimmune disease or immunocompromising condition-5%
Organ System Involved
71% of children had involvement of at least four organ systems.[4]
The most common organ system involved in MIS-C children among a total of 186 children were.[4]
An individual aged <21 years presenting with fever, laboratory evidence of inflammation**, and evidence of clinically severe illness requiring hospitalization, with multisystem (>2) organ involvement (cardiac, renal, respiratory, hematologic, gastrointestinal, dermatologic or neurological);[6]
AND
No alternative plausible diagnoses;
AND
Positive for current or recent SARS-CoV-2 infection by RT-PCR, serology, or antigen test; or exposure to a suspected or confirmed COVID-19 case within the 4 weeks prior to the onset of symptoms.
Elevation of inflammatory markers including ESR, C reactive protein and procalcitonin are usually seen in MIS-C. Increased level of Interleukin-6 (IL-6), Interleukin-10(IL-10) d-dimer, serum ferritin, prothrombin time have also been seen in MIS-C.[1]
Aspirin has been used primarily for its antiplatelet effect. It is recommended in all patients with MIS-C.[7][8]
Anakinra is considered if fevers last more than 24 hours post steroids/IVIG or in the moderate or severe presentation.[7][8]
Tocilizumab is also considered if fevers last more than 24 hours post steroids/IVIG or in the moderate or severe presentation.[7][8]
Empiric antibiotics like vancomycin, ceftriaxone, and clindamycin are given for community-acquired shock presentation until cultures are negative for 48 hours.[7][8]
↑ 4.004.014.024.034.044.054.064.074.084.094.104.114.12Feldstein, Leora R.; Rose, Erica B.; Horwitz, Steven M.; Collins, Jennifer P.; Newhams, Margaret M.; Son, Mary Beth F.; Newburger, Jane W.; Kleinman, Lawrence C.; Heidemann, Sabrina M.; Martin, Amarilis A.; Singh, Aalok R.; Li, Simon; Tarquinio, Keiko M.; Jaggi, Preeti; Oster, Matthew E.; Zackai, Sheemon P.; Gillen, Jennifer; Ratner, Adam J.; Walsh, Rowan F.; Fitzgerald, Julie C.; Keenaghan, Michael A.; Alharash, Hussam; Doymaz, Sule; Clouser, Katharine N.; Giuliano, John S.; Gupta, Anjali; Parker, Robert M.; Maddux, Aline B.; Havalad, Vinod; Ramsingh, Stacy; Bukulmez, Hulya; Bradford, Tamara T.; Smith, Lincoln S.; Tenforde, Mark W.; Carroll, Christopher L.; Riggs, Becky J.; Gertz, Shira J.; Daube, Ariel; Lansell, Amanda; Coronado Munoz, Alvaro; Hobbs, Charlotte V.; Marohn, Kimberly L.; Halasa, Natasha B.; Patel, Manish M.; Randolph, Adrienne G. (2020). "Multisystem Inflammatory Syndrome in U.S. Children and Adolescents". New England Journal of Medicine. doi:10.1056/NEJMoa2021680. ISSN0028-4793.
Presentation of COVID-19 is less severe in children as compared to adults. Most of the children are asymptomatic.[1]
According to CDC, as of April 2, 2020, 1.7% confirmed cases of COVID-19 were reported in children aged <18 years age among the total number of confirmed cases of COVID-19.
COVID-19 in children could range from asymptomatic presentation to mild to severe disease.
The incubation period of SARS-CoV-2 varies from 2 to 14 days with most patients developing symptoms 3 to 7 days after exposure.[1]
Symptoms
Fever and Cough are one of the most common symptoms reported in children. One study showed fever is prevalent in 47.5% of children and cough in 41.5% among the 1124 children with COVID-19. According to the CDC, fever, and cough was reported in 56% and 54% of children with COVID 19
Dyspnea, nasal congestion, pharyngeal erythema, and sore throat are also common presentations in children.
Gastrointestinal symptoms-The gastrointestinal manifestation in COVID-19 positive children are diarrhea, vomiting, abdominal pain, nausea, and anorexia. Children can present with gastrointestinal symptoms in the absence of respiratory symptoms.
Cutaneous Findings- The cutaneous findings in COVID-19 positive children range from petechiae to papulovesicular rashes to diffuse urticaria. These appear early in the course of COVID-19 and result secondary to viral replication or circulating cytokines. Many patients with COVID-19 are presenting with chilblains like lesions unrelated to cold. Chilblains are painful or itchy swellings of the toes and fingers, caused by small-vessel inflammation from repeated exposure to cold. A retrospective case series presented 22 children and adolescents with COVID-19 who presented with chillblains lesions. [2][3]
Neurological manifestation- The presentation of neurological manifestation in children is rare. However, a case report described a rare case of a 6-week old infant with COVID-19 who had 10-15 seconds episodes of upward gaze and bilateral leg stiffening.[4]
Neonates and Infants with COVID-19 are often asymptomatic or present with fever with or without mild cough and congestion.
Severity of Disease in Children with COVID-19
Asymptomatic presentation-
A large number of children with COVID-19 are asymptomatic.
According to one study 14.2% of children were asymptomatic. Another study showed 18% of asymptomatic children with COVID-19.
Mild Disease
Few numbers of children also present with mild manifestations of COVID-19.
A study showed 36.3% of children present with a mild form of the disease.
Moderate
Severe
2.1% of children present with a severe form of COVID-19 disease.
Children with underlying comorbidities are more susceptible to getting severe COVID-19 disease.
According to recent evidence, it is suggested that children with MISC had antibodies against COVID-19 suggesting children had COVID-19 infection in the past.
This syndrome appears to be similar in presentation to Kawasaki disease, hence also called Kawasaki -like a disease. It also shares features with staphylococcal and streptococcal toxic shock syndromes, bacterial sepsis, and macrophage activation syndromes. "www.rcpch.ac.uk"(PDF).
Epidemiology and Demographics
According to a recent study among the 186 children with MIS-C, the rate of hospitalization was 12% between March 16 and April 15 and 88% between April 16 and May 20.
80% of the children were admitted to the intensive care unit and 20% of the children required mechanical ventilation.
4% of the children required extracorporeal membrane oxygenation.
The mortality rate among 186 children with MIS-C was 2%.
Age
Among the 186 children with MIS-C distribution of age group was
<1yr-7%
1-4yr-28%
5-9yr-25%
10-14yr-24%
15-20yr-16%.
Gender
Among the 186 children with MIS-C
Comorbidities
Children with MIS-C had following underlying comorbidities.
Clinically diagnosed Obesity-8%
BMI-Based Obesity-29%
Cardiovascular diasease-3%
Respiratory disease-18%
Autoimmune disease or immunocompromising condition-5%
Organ System Involved
71% of children had involvement of at least four organ systems.
The most common organ system involved in MIS-C children among a total of 183 children were.
Evidence of COVID-19 (RT-PCR, antigen test or serology-positive), or likely contact with patients with COVID-19
Treatment
All the children with MIS-C are treated as suspected COVID-19.
Mild to Moderate cases of MIS-C are managed supportively.
Anti-inflammatory treatments with Intravenous immunoglobulin(IVIG) with or without corticosteroids have shown a good response rate.[6]
Aspirin has been used primarily for its antiplatelet effect.[6]
The antiviral therapy where required are only given in the context of clinical trials(Eg RECOVERY TRIAL).
Empiric antibiotics like vancomycin, ceftriaxone, and clindamycin are given for community-acquired shock presentation until cultures are negative for 48 hours."www.childrensmn.org"(PDF).
Fluid resuscitation in 10 ml/kg aliquots with reevaluation after each bolus. Maintain euvolemia. Avoid hypervolemia.
Prevention of MIS-C
MIS-C can be prevented by reducing the risk of child exposure to COVID-19 infection.
An observational prospective study found out that the incidence of HIV-infected individuals to be affected by SARS-CoV-2 was similar to the general population.
Specific antiretroviral therapy did not affect COVID-19 severity.
Immunosuppression(low CD4 cell counts) was associated with COVID-19 severity.
Patients with HIV infection often have other comorbidities(lung disease, cardiovascular disease) therefore, increasing the risk for severe-COVID-19 disease.
↑ 6.06.1Rajapakse, Nipunie; Dixit, Devika (2020). "Human and novel coronavirus infections in children: a review". Paediatrics and International Child Health: 1–20. doi:10.1080/20469047.2020.1781356. ISSN2046-9047.
↑Belhadjer, Zahra; Méot, Mathilde; Bajolle, Fanny; Khraiche, Diala; Legendre, Antoine; Abakka, Samya; Auriau, Johanne; Grimaud, Marion; Oualha, Mehdi; Beghetti, Maurice; Wacker, Julie; Ovaert, Caroline; Hascoet, Sebastien; Selegny, Maëlle; Malekzadeh-Milani, Sophie; Maltret, Alice; Bosser, Gilles; Giroux, Nathan; Bonnemains, Laurent; Bordet, Jeanne; Di Filippo, Sylvie; Mauran, Pierre; Falcon-Eicher, Sylvie; Thambo, Jean-Benoît; Lefort, Bruno; Moceri, Pamela; Houyel, Lucile; Renolleau, Sylvain; Bonnet, Damien (2020). "Acute heart failure in multisystem inflammatory syndrome in children (MIS-C) in the context of global SARS-CoV-2 pandemic". Circulation. doi:10.1161/CIRCULATIONAHA.120.048360. ISSN0009-7322.