You don't say what the "usual steroid reduction route" is. But it sounds as if it is too fast for you - as it seems to be for very many patients. You aren't that unusual - I was barely 52 when it started and I know a lot of others in their 50s. If you visit the other UK PMR forums you will "meet" others who were also young at the start. You will find links here:
https://patient.info/forums/discuss/pmr-gca-and-other-website-addresses-35316
The AVERAGE age of onset is said to be 73 - but since half of 80 year olds have it that requires quite a few younger people to being that average down. However - many of us think that many of the younger patients are misdiagnosed and labelled as menopausal, fibromyalgia, depression and a few other misnomers.
Here is a slow reduction that is working for many. Go back to the last dose you were pain-free at and start again with this sort of reduction:
A group of us worked out reduction schemes individually that have allowed us to reduce far further than ever before but they are all basically the same - and they were based on a scheme a Swedish gentleman worked out when he simply couldn't get below 3mg without pain. Img at that level is 33%, 1/2mg is 17% - way above the 10% that has been recommended for years. So he used a table to see the daily doses and took the new dose on one day, old dose for a few days and then proceeded by repeating that and then reducing the number of days of old dose - until he got to everyday new dose. It worked, he got off pred and has been off pred for at least 3 years (it could be longer). Something similar to mine is being tried by a consultant rheumatologist in the north of England and he too finds it works for every single patient he has given it to, as it have done for several ladies beforehand.
My reductions are VERY slow. I use the following pattern to reduce each 1mg:
1 day new dose, 6 days old dose
1 day new dose, 5 days old dose
1 day new dose, 4 days old dose
1 day new dose, 3 days old dose
1 day new dose, 2 days old dose
1 day new dose, 1 day old dose
1 day old dose, 2 days new dose
1 day old dose, 3 days new dose
1 day old dose, 4 days new dose
1 day old dose, 5 days new dose
1 day old dose, 6 days new dose
By that stage if I feel OK I feel safe to go all new dose. I suppose you might be OK starting and stopping at "1 day new, 4 days old" but I was terribly sensitive to steroid withdrawal pain so I err on the safe side. Once you get to the "everyday new dose" - if you feel OK you can start on the next reduction, no real need to spend a month at the new dose.
This avoids steroid withdrawal pain - which is so similar to PMR pain that you often can't tell which is which and some of us suspect that many flares are NOT the PMR returning but problems with steroid withdrawal. Using a scheme like this also means you can stop immediately if you have any problems - you might be fine at one day old dose, 2 days new (lower) dose but not at a 3 day gap - but you have dropped your dose a lot and that is the idea. It also isn't as slow as you would think - you can reduce at a rate of about 1mg/month on a continual basis.
The Bristol group starts new patients with PMR with 6 weeks 15mg, 6 weeks at 12.5mg and then a year at 10mg before continuing the reduction and that achieves a far lower rate of flare (20% instead of 60%). I suspect their flares then come below 10mg as they do the 1mg at a time reduction. Just below 10mg is a common dose for people to get stuck at - and I (and others) believe it is because even 10% drops are too much for many patients. These patients are then labelled as "steroid resistant" or told they need methotrexate to help them reduce but we have seen this slow reduction work for those patients too. We believe that methotrexate (MTX) works for patients who have late onset rheumatoid arthritis (LORA) or LORA and PMR together. Very few patients get off pred altogether when taking the MTX – we suspect those who do are probably the mis-diagnosed LORA patients - or another arthritis that responds to MTX.
This reduction scheme is being used by quite a few members of the PMR/GCA UK forums (both of them) and the feedback to date has been good: people are being able to reduce without discomfort so they have stopped worrying about “flares” which probably also contributes to their well-being.