Since its initial description in December 2019 in Wuhan , China, Corona virus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), has rapidly evolved into a worldwide pandemic affecting millions of lives .

Unlike adults, the vast majority of children with COVID-19 have mild symptoms. However, there are children who have significant respiratory disease, and some children may develop a hyper inflammatory response similar to what has been observed in adults with COVID-19. Furthermore, in late April 2020, reports emerged of children with a different clinical syndrome resembling Kawasaki disease (KD) and toxic shock syndrome; these patients frequently had evidence of prior exposure to SARS-CoV-2.

The pathophysiology of MIS-C:

Is unclear ,but it appears to be a consequence of a exacerbated immune system response or maladaptive response of the host .After the virus enters the human cells, the first line of defense against infection should be a quick and well-coordinated immune response ;however, when this mechanism is unregulated and excessive ,hyper inflammation can occur.

Cytokines that play an important role in inducing immunity and immunopathology during infections in excess can cause the clinical syndrome known as cytokine storm. The inflammatory response caused by SARS-CoV-2appears to be the major cause of mortality in infected patients .

The infection of dendritic cells or macrophages by SARS-CoV-2 induces the production of low levels of antiviral cytokines and increases the production of inflammatory cytokines (tumor necrosis factor[TNF], interleukin[IL]-1, IL-6,and interferon ).

Inclusion Criteria:

Any suspected case of MIS-C from birth to 12 year included both sexes fulfill criteria of MIS-C (WHO) .

1. Fever for ≥3 days.

2. Clinical signs of multi system involvement (at least 2 of the following):

   1. Rash, bilateral non purulent conjunctivitis, or mucocutaneou inflammation signs (oral, hands, or feet)
   2. Hypotension or shock
   3. Cardiac dysfunction, pericarditis, valvulitis , or coronary abnormalities (including echocardiographic findings or elevated troponin)
   4. Evidence of coagulopathy (prolonged PT or PTT)
   5. Acute gastrointestinal symptoms (diarrhea , vomiting, or abdominal pain)

4. Elevated markers of inflammation (eg ESR, CRP) 5. No other obvious microbial cause of inflammation. 6. Evidence of SARS-CoV-2 infection (Any of the following: Positive SARS-CoV-2 RT-PCR ,positive serology, COVID 19 exposure within the 4 weeks prior to the onset of symptoms).

according to CDC criteria exposure to a patients with suspected or confirmed COVID-19 within the 4 weeks prior to the onset of symptoms.

Exclusion Criteria:

• Other obvious microbial cause of inflammation, including bacterial sepsis and staphylococcal/streptococcal toxic shock syndromes.

Multisystem inflammatory syndrome in children