How do you handle fatigue caused by your psoriatic arthritis?

Hello all,

My son was diagnosed with psoriatic arthritis late last year and it's been a big adjustment for him. He's in his early twenties and living on his own and working now so he's been managing it on his own. He used to be very active and into sport, but since he started working plus the lockdown he has had to put it all aside. His work has taken up a lot of space in his life and he doesn't have time for sport anymore. Apparently his flares have been worse and the fatigue is doing a number on him, he only seems to be able to manage work, sleep, and take his medicines. The medicines take care of the pain, but the fatigue is overwhelming him and it's now starting to take its toll on his work.

Have any of you have found solutions to fatigue? How do you manage it in addition to work or your daily life? 

I told him to contact his rheumatologist, but he is resisting, thinking that he can handle it himself. Is there any hope for him?

Thanks in advance,
Jack