Psoriatic Arthritis Info

What you're feeling

Psoriatic arthritis tends to creep in rather than announce itself. You might notice that one or more joints (often in the fingers, but also the wrist or elbow) have become stiff and achy, and that the stiffness is worst first thing in the morning or after sitting still, easing once you get moving. That pattern, of stiffness that loosens with use, is a clue that the problem is inflammatory rather than simple wear and tear.

A few features are especially characteristic. A whole finger (or toe) can swell up like a little sausage, and this is called dactylitis; it can be tender and make the digit hard to bend. You may see changes in your nails: tiny pits or dents, ridging, a yellowish lifting of the nail away from its bed, or crumbling at the edge. The end joints of the fingers, those nearest the nail, are often involved, which is a little unusual for inflammatory arthritis and a useful pointer for your doctor. Some people also get pain right where a tendon attaches to the bone, such as at the elbow or the back of the heel.

Many people with psoriatic arthritis also live with the skin condition psoriasis, with patches of red, scaly skin, often on the elbows, knees or scalp. The joint trouble can begin before the skin changes, after them, or without any obvious skin involvement at all. Alongside the joints, a deep fatigue is common and can be one of the most wearing parts of the condition.

(If your main concern is rheumatoid arthritis or a more general inflammatory joint problem, see our separate page on inflammatory and rheumatoid arthritis; psoriatic arthritis is a distinct condition, even though they can look alike.)

What's actually happening

Psoriatic arthritis is an immune-driven condition. Instead of defending the body, the immune system mistakenly attacks your own tissues and drives inflammation. The same misdirected process that causes the scaly skin of psoriasis can also target the joints and, distinctively, the entheses, the small zones where tendons and ligaments anchor onto bone.

That inflammation is what you feel as swelling, stiffness and pain. The sausage-like swelling of a whole finger comes from inflammation in the joints and the tendon sheaths along the digit all at once. The nail changes and the involvement of the end finger joints reflect how closely the nail, the skin and that last joint are connected.

This is not osteoarthritis, the "wear-and-tear" arthritis that comes with age and overuse; it is not the same as rheumatoid arthritis, although the two inflammatory conditions can resemble each other. The important point is that psoriatic arthritis is active and ongoing: if the inflammation is left unchecked over years, it can gradually damage and even deform the joints. The good news is that the process is treatable, and bringing the immune activity under control protects the joints from that damage.

What we can do about it

Diagnosis is usually made by a rheumatologist, a specialist in inflammatory joint disease. There is no single blood test that confirms psoriatic arthritis, so the diagnosis is pieced together from your story, an examination of the joints, nails and skin, and imaging such as X-rays or ultrasound. Telling it apart from other kinds of arthritis matters, because it changes the treatment.

The mainstay of treatment is medical, led by rheumatology, and aimed at calming the immune process itself:

• Disease-modifying drugs (DMARDs) such as methotrexate are often the first step. These dampen the overactive immune response and protect the joints over the long term.
• Biologic and targeted medicines are used when DMARDs aren't enough, or for more aggressive disease. These are precision drugs that block the specific immune signals driving the inflammation, and they can be very effective for the joints, the entheses and the skin together.
• Treating the skin psoriasis goes hand in hand with treating the joints, and is often coordinated with a dermatologist.
• Hand therapy and exercise keep the joints moving, maintain grip and function, and help with stiffness and fatigue.

Surgery has a role, but a limited one, mainly for joints that have already been damaged or deformed by years of inflammation, where the aim is to restore function or relieve pain. Even then, the medical treatment to control the disease continues. The single most important message is that early treatment protects the joints: the sooner the inflammation is controlled, the less lasting damage is done.

What to expect

Psoriatic arthritis is a long-term condition rather than something that is cured once and forgotten, but it is very treatable, and most people who start treatment early do well. The goal of modern care is to quieten the disease so completely that the joints feel and function close to normal, and for many people that is achievable.

Because it is driven by the immune system, treatment is usually ongoing, and it can take some adjusting to find the medicine, or combination, that suits you best. The condition can wax and wane, with quieter spells and occasional flares. Staying in regular contact with your rheumatologist matters, both to keep the inflammation suppressed and to monitor the medicines. The trade-off for that long-term commitment is real protection: keeping the inflammation down preserves your grip, your hand function and your joints for the years ahead.

When to see someone

• Joint pain or swelling with morning stiffness, especially if a whole finger swells up or the stiffness eases as you move: this deserves assessment, ideally by a rheumatologist.
• Psoriasis plus new joint symptoms. If you already have psoriasis and your joints start to ache, swell or stiffen, mention it to your doctor; the link is important and easy to miss.
• Nail changes such as pitting, ridging, crumbling or the nail lifting away from its bed, particularly alongside joint or end-finger-joint pain.
• Pain where a tendon meets the bone (for example at the elbow or heel) that isn't settling.
• Joints becoming stiff, deformed or harder to use over time: a sign the disease may not be fully controlled, and worth reviewing so treatment can be stepped up before more damage occurs.