Chicago Fire: What Illness Does Otis Have?
Real-life firefighters work in a field that sometimes requires them to put their very lives on the line, and "Chicago Fire" reflects the inherent risks of its principal firefighters' chosen profession. That said, as a soap opera-adjacent serial drama, it's not just fires that threaten its characters' lives but all sorts of everyday dangers too. "Chicago Fire" introduces Otis Zvonecek (Yuriy Sardarov) as one of its core firefighters in its pilot episode and bids him farewell in Season 8, Episode 1. His exit is the result of an accident during a firefighting job that saddles him with an injury that turns out to be fatal.
Before Otis dies, he struggles with a serious illness midway through Season 4 that physically manifests in sizable bruises on his body. After some hesitancy over properly diagnosing the issue due to fearing that it will put his career in jeopardy, he ends up learning from a doctor that he's experiencing a blood disorder called immune thrombocytopenic purpura, abbreviated ITP.
This isn't Otis' only health complication over the course of his "Chicago Fire" story arc — for example, in Season 6, a gunshot wound impacts his ability to walk without assistance. By the time he dies, then, Otis has survived multiple life-threatening scenarios including his ITP diagnosis, making his untimely end all the more tragic.
Otis' illness is unrelated to his death
It's entirely possible that the scene in which Otis reveals his ITP diagnosis in "Chicago Fire" Season 4 is plenty of viewers' first exposure to this particular disease. As it turns out, a nonprofit called the Platelet Disorder Support Association spotlighted this "Chicago Fire" storyline on its official website for its inclusion of the illness.
In effect, Otis's storyline serves fictional representation of the fact that it's possible to treat and move forward from an ITP diagnosis. After Season 4, Otis is in decent shape until his gunshot wound two seasons later. Even then, he's able to remain at Firehouse 51 and eventually continue to fight fires until the accident that costs him his life in the Season 8 premiere.
While a sad end for a character that both survived considerable danger and endeared himself to numerous viewers, Sardarov shared in an interview with Tell-Tale TV that part of the rationale behind Ortis' death was his own desire to move on to new opportunities. "It was a combination of me wanting to move on and them needing something akin to what's going to happen," he said. "And I think those two things met at the perfect time."
Otis' struggles with ITP, then, are confined entirely to Season 4, before a series of injuries on the job prove to be altogether more impactful and ultimately fatal.