A seven-year-old boy has survived a rare life-threatening post-COVID-19 complication called "hyper -inflammatory syndrome" with which he was diagnosed at a city hospital, doctors said on Friday.

The boy, son of a Pune Municipal Corporation worker, along with his parents and brother had contracted COVID-19 three weeks ago, but all of them had recovered from the infection.

Hyper-inflammatory syndrome is associated with COVID- 19. The life-threatening illness is characterised by inflammation in the entire body, including vital organs.

According to doctors at a private hospital, the boy was admitted to the pediatric ICU on August 10 after complaining of fever, pain in abdomen and vomiting for two days.

Dr Bhakti Sarangi, one of the doctors who treated the boy, said his condition was critical with high pulse rate (142/min), high respiratory rate 26/min and low blood pressure.

"Our initial diagnosis was 'hyper-inflammatory syndrome', a post-COVID-19 complication. However, we also suspected other diseases like dengue, septic shock that have similar features.

"In the initial stage of treatment, the boy received saline, oxygen and various injections to increases pumping of the heart and to normalise blood pressure," she said.

She said since the boy's inflammatory markers, neutrophils of white blood cells, cardiac enzyme and coagulation parameters were elevated, he was treated with steroid injection on the second day of admission.

"As his breathing deteriorated further, he was put on a non-invasive ventilator. His CT scan revealed dilated intestines, enlarged liver and spleen.

"His hearts left coronary artery was dilated. Thus, he had heart, lungs, abdomen and liver injury, suggesting multi-organ involvement," said Dr Jitendra Oswal, another doctor who treated the boy.

Oswal said since the boy's symptoms persisted on the third day also, he was given immunoglobulin injection.

"But his condition did not improve as an inflammatory substance called interleukin-6 (IL-6) level was extremely highin his blood," he said.

He said the boy was then given Tocilizumab injection (which blocks IL-6 receptors and stops inflammation) and he responded dramatically with fever and abdominal pain disappearing in 12 hours.

"All his inflammatory markers, including IL-6 level, started showing normalising trend. He was discharged after 11 days of stay in the hospital," he added.

Dr Oswal said they are expecting many such cases in coming weeks as COVID-19 cases are rapidly rising.

"Parents and paediatricians should be aware and watchful of this rare hyper-inflammatory syndrome which is a post COVID-19 complication. Early recognition and treatment can save lives," he said.