Hi, I'm a newbie looking for a bit of advice please...

I receive PIP enhanced living and standard mobility allowance and i hold a disabilty blue badge. I have just written to DWP to see if they will change me to enhanced mobilty now as my walking has got increasingly worse over the last 3 months and I'm now unable to walk more than a dozen steps with my crutches without pain and fatigue... my question however is this... I have remitting and relapsing MS and my conditions can get dramatically worse or can improve a little... a relapse usually lasts around 6 months and then I'll recover a little whilst in remission before the whole cycle begins again, my concern is whether I should be telling the DWP everytime I'm in remission and risk them stopping my PIP only to have to reapply when I relapse again, which is inevitable. My disease is lifelong, debilitating and incurable but I have good months and bad months... I don't want to be accused of fraud when I'm in remission but worry if I stop my PIP I'll then end up having to start the whole year-long process all over again... what are people's thoughts on this please? Many thanks.