Psoriatic arthritis and spondyloarthritis are the two types of arthritis where you can get a rebound flare from prednisolone, even when you taper slowly. 
I was on it for about 6 months, tapering from 40mg to 10mg quickly, from 10-5 a bit more slowly, then a month on 5mg while trying to get my symptoms stable under methotrexate. Then 5 weeks to taper to nothing, leaving my spondyloarthritis un-medicated.
Initially it was okay, a bit of stiffness, especially in the mornings.
But then summer hit.
I’m always get worse in the heat.
What happens during a prednisolone rebound?
It depends on your flavor of arthritis.
For psoriatic arthritis, it will usually start in the hands and feet – finger and toe joints and heel/achilles tendon will get inflamed, sometimes looking like sausages (dactylitis).
Or if you have skin involvement, the psoriasis will flare. 
For a mild rebound, this may be all that happens.
In a strong one, like what I have at the moment, every single joint, every tendon, every piece of cartilage becomes inflamed. Even the tendons behind and above my eye are swollen, stiff and very painful.
Joints can also get inflamed (bursitis and synovitis), not just the tendons.
The spine can get involved if you have spondyloarthritis.
A rebound can include your eyes, causing conjunctivitis (pink eye), iritis or uveitis.
The swelling around the nerves can cause burning or spiking pain in various locations, typically hands and feet.
The swelling around the lymph system can cause edema, resulting in more swelling and stiffness. Especially if you have any areas that have already been damaged, such as with multiple sprains of the same joint.
I bet that inflammatory bowel disease would also flare, but I had that under control with probiotics before finishing the prednisolone.
Some people can also get extreme fatigue, a fever and chills.
From what I’ve read, prednisolone rebound can last months after finishing a longer or high dose course.
How is it treated?
Ibuprofen and stronger NSAIDs are not recommended for tendon inflammation (tendonitis) because they delay healing.
There isn’t much you can do for enthesitis (where the tendon attaches to the bone), and it can be exquisitely painful, especially in the feet. Infliximab and etanercept are the only two medications which seemed to help severe enthesitis. 
Chondritis is normally treated with anti-inflammatories, or cortisone injections, risking another rebound, or compounding an existing one.
Dactylitis is also difficult to treat, with infliximab having the best results. 
And although these are often prescribed, methotrexate, NSAIDs, and long term prednisolone are not recommended for either psoriatic arthritis or ankylosing spondylitis with spinal involvement, due to the lack of supporting positive results in scientific studies. [1,3,4,6,7]
I have no ankles – the achilles tendon has swelled to the width of my ankles, and my foot has swelled up like a balloon. Walking is terribly painful, and I have only one pair of shoes which fit (low-profile mary janes, very adjustable).
Standing from sitting, or standing up from my futon bed is very difficult as the tendons, muscles and joints in and around my knees and hips have visibly swollen.
Kneeling? Forget it.
Putting shoes and socks on? I don’t bend enough to reach, and my hands are too painful to hold the socks.
My eyes are quite red and I’m looking rather cave-man-ish, with swollen brows and jaw. The pressure causes headaches.
My hands are useless – the fingers don’t bend properly and I have no grip strength. The knuckles feel like they’ll pop, and the pain on any applied pressure is incredible.
Putting a hair band around my hair? I could scream.
I’ve lost a lot of range of motion in my shoulders, with pain on movement that takes my breath away, mostly in the acromioclavicular joint. It’s hard to find a position to sleep.
Closing or opening a bra? Nope.
I have to be careful about my posture and breathing, because the costochondritis is constantly on edge. When it goes, I do take an ibuprofen and lie on a heat pack – my usual tricks to keep costo under control.
Lower back and cervical spine have recently joined in, becoming very stiff (but not really ‘sore’).
Despite the summer heat, I often have chills and a slight fever.
It’s difficult to walk, use my hands in any way, move my eyes, and breathe. It’s truly disabling.
What helps prednisolone rebound?
I don’t know.
Pain killers don’t touch the pain.
Ibuprofen seems to only help the cartilage inflammation (nose/costochondritis), not the rest of the ‘itises.
What I’ve found
- Exercising in water does feel good and helps with range of motion, while I’m doing it. I stiffen up after class quickly though.
- An ice pack on my feet helps with the burning, and to get to sleep on hot nights. Anywhere else, it provides a little pain relief but adds heaps of stiffness.
- A heat pack helps my spine and the costochondritis, but is uncomfortable in the heat of summer. Anywhere else and it makes the swelling and pain worse.
- Deep breathing keeps my lungs expanding with less pain than if I breathe into my belly. This is worst in the mornings.
- Hot weather makes it worse, possibly through increased edema. Lymphatic drainage massage can help a little to reduce the edema.
- Lymphatic drainage massage helps reduce the edema, but does nothing for the inflammation. It is relaxing though.
One physio has said there is nothing that can be done – I should avoid stronger forms of massage, avoid stretching strenuously, avoid exercising (except in water). And that with enthesitis and tendonitis, you should rest a lot, and switch between lying down and gentle movements regularly.
If you find that something helps, other than going back on prednisolone or starting infliximab, please do let me know!