Tomura Shigaraki did not take care of himself.
This went beyond the obvious need for chapstick.
The only time in the whole series that he acknowledged his physical need and addressed it accordingly was when he woke up from the tank. He felt cold so he found a blanket/cape to wrap around himself. Like a normal person would.
Most of the time, he ignored basic physical needs.
He ate very little. In his introductory manga frame, we are shown the back of his neck, his spine protruding, signaling emaciation.
When Stain stabbed him in the shoulder, Tomura proceeded to run around Hosu with a hole in his shirt and a wound on his shoulder.
He either had a high pain tolerance or he gets off on mistreating himself. Or both.
When he's fighting Gigantomachia, sleep deprivation did not dempen his mood. He was having the time of his life.
After his quirk awakening, he pushed Decay as far as he could. Blood squirted from his nostrils as he laughed out his catharsis.
At the end of his fight with Re-distro, he had lost two fingers, bloody and limping, Tomura still couldn't wipe that grin off his face. It felt good to feel like crap.
Tomura did not care much for his physical appearance. The pimped-out outfit as the PLF Grand Commander was likely picked out by someone else.
When Dabi got a new frock for the final war, Tomura was in rags. He probably hadn't changed or showered since he fought Star.
He desprately tried to detach himself from his own humanity.
Because a monster such as him did not deserve a shred of comfort, let alone redemption.
So, Tomura Shigaraki would not and could not take care of himself.
