Beware of the ambiguous enemy of multisystem inflammatory syndrome in adult (MIS‐A) following Covid‐19 infection or vaccination

Multisystem Inflammatory Syndrome is a rare and novel clinical presentation described during the evolving COVID‐19 pandemic. The condition is usually presenting as a sepsis‐like syndrome leading to secondary multi‐organ dysfunction post–COVID‐19 infection. Although the syndrome has been mainly described in children, rare adults' form has been similarly described. We are describing a 37‐year‐old female patient presented with fever and neck pain after 1 month of a mild SARS‐CoV‐2 infection course and 10 days post her second COVID‐19 vaccine. Examination demonstrated fever, hypotension, and hypoxemia, in addition to multiple tender cervical lymph nodes. Initial laboratory workup showed evidence of significant inflammation with raised markers, including C‐reactive protein, ferritin, and interleukin‐6. Extensive evaluation to rule out active infection was done, and all return negative, including repeat SARS‐CoV‐2 test. Furthermore, cardiac evaluation showed moderately reduced systolic ventricular function. Despite all negative test and supportive measures, the patient continued to deteriorate requiring critical care admission for ionotropic support, non‐invasive ventilation in addition to presumptive broad‐spectrum antimicrobial management. There was no significant improvement with supportive care until the presentation of multisystem involvement on in the context of a recent history of COVID 19 and negative infective screen was raised. The diagnosis of multisystem inflammatory syndrome‐adult form (MIS‐A) was embraced, and the patient was commenced on methylprednisolone leading to a dramatic resolution of symptoms both clinically and biochemically with stabilization of vital functions allowing for safe outcomes.