It's not the first time they've seen a child develop this syndrome after catching Covid-19, and now Logan's mother, Jessica Walsh, is calling for health experts to spread the word of this dangerous side effect.
Walsh took her son to the emergency ward in December after he vomited and became feverish.
They were sent home, with emergency staff classing it as a stomach bug.
However, just days later Logan's condition worsened. By December 16 blisters and rashes covered his body and his extremities were swelling. His blood had also thinned.
Walsh's GP told her to call an ambulance.
In hospital, Logan didn't urinate for 12 hours and the rash continued to spread.
After a specialist was called in, he was diagnosed with PIMS-TS, which can cause organ failure, insufficient blood flow, and heart problems.
"The syndrome is known to attack organs, with the heart being the main one," Walsh said.
So I shared a little video of my 7 year old son after he contracted the illness PIMS-TS, now I want to share some...
Posted by Jessica Jay Walsh on Saturday, December 26, 2020
She took to social media, angry that UK Government health advice doesn't warn about this potentially deadly side effect of Covid-19 in children.
"The doctors told me they were seeing children and teenagers who had already had Covid-19, showing no symptoms when they had it and then coming in later, just like Logan," she said.
"They go on all the time about how this pandemic only affects the elderly and often say it doesn't seem to affect children.
"When this first began happening [to Logan], not all doctors were able to recognise it, and the link in the condition to Covid-19 is only just starting to be taken seriously."
After a stint in the ICU ward where he was given steroids, Logan was sent to rehabilitation to relearn how to walk.
"As his joints and muscles had swollen, Logan now requires physio to help with rehabilitation, and to walk again," Walsh said.
"Thankfully, the initial treatment eventually got his condition under control ... Logan is recovering slowly, and made it home on Christmas Day."