Most of my self-treatment of my psoriatic arthritis is aimed at improving the inner workings of my body, to improve it at the root rather than at the surface where it is seen or felt. This tactic has done wonders to improve both the psoriasis and the arthritis aspects of the condition.
However, there always remains some discomfort that needs to be treated where it is felt. For the skin this can be in the form of topical lotions, moisturisers etc. For the joints it may be the use of heating pads, infrared heating devices and similar methods, or the normal smelly arthritis rubs to deaden the pain.
The problem with this condition is that you might well have psoriasis on the skin in the same area that you have joint pain. If you apply one of the muscle and joint creams onto psoriasis lesions the result is likely to be intense pain and cause you to rush to the bathroom to wash off the cream. Been there, done that, felt the pain and got the T-shirt. It gives new meaning to the saying used in gyms that you should "feel the burn".
Aside from my daily consumption of glucosamine/condroitin/hyaluronic acid, I do something else to ease my joint deterioration, thereby attempting to keep my joints serviceable for many years to come.
I noticed years ago that my joints seemed to be wanting to always go to the bent position. I also noticed that the people with the worst arthritis conditions were bent over or had very bent joints. I did some research on it at the time but can't remember where I found the info that I wanted, which brought me to my conclusions. Wherever it was, it was enough to make me experiment by keeping my joints straight whenever possible. The result has been long-term easing of my arthritis symptoms, although ageing will probably eventually cause natural deterioration to start catching up again.
Observe your own habits and think about how they may be aggravating your arthritis symptoms. I noticed various that I will list below.
Hands. At rest my hands naturally go into the closed position of a loose fist. Look at most severely arthritic people and you will see that their fingers are curled like claws. Once they get to that stage it is very difficult to do even simple everyday tasks because your fingers will not do what you want them to do. I changed my resting and sleeping habits to remedy this. Instead of letting my hands rest as they naturally would, I lie them palm down against a flattish surface, like the bed, top of the settee or my thigh. In this position the fingers must straighten and to help them do this I spread them apart against the surface. Each time that I wake at night I put them back in those positions if they have moved. It did not take long before I would wake to find them still straight.
I also actively stretch my wrists and fingers regularly by pressing them hard against a wall or door frame, with fingers spread and arm at 90 degrees to the surface. This stretches the ligaments to help the joints stay straight. It is also very good for carpal tunnel syndrome, if you spend too much time at the keyboard.
Spine. In bed it can be very comfortable to be curled up in a ball, with legs pulled up toward your chest. This is not good for your spine, which will gradually grow into the curved shape and not want to straighten. I try to always sleep with my back straight or slightly arched backward. I find it particularly beneficial to arch my spine backward as far as I can for a few minutes immediately before I get out of bed. I will have less back pain when I stand up than if I don't do this.
Legs. Getting back to curling up in a ball in bed, this bends your hips at 90 degrees or more one way and your knees even more the other way. This will not help your hips or your knees. I found it best to sleep on my side with a small amount of angle, maybe 20-30 degrees, to my hips and knees. This stops me from falling over onto my back or stomach and is near enough to straight that my joints don't freeze into a bent position when I want to get up.
Sitting for long periods is bad for spine, hips and knees. All end up bent and may not want to straighten up later when you need to stand up. I try to limit the periods that I am sitting by standing up and walking around for awhile. Changing from a sit-down task like computer work to a stand-up task like filing documents for awhile helps big time. Doing some leg and back stretches when you change from the sitting to standing work also helps.
So, think about your posture habits and what you can do to improve them. Your joints will thank you by serving you longer and without shouting painfully at you.