Psoriatic arthritis (PsA) is an inflammatory joint condition that can occur after an individual has had psoriasis for a long time. Less frequently it can occur at the same time as psoriasis develops and can even occur without the skin manifestations of psoriasis.

Not everyone with psoriasis develops arthritis. Arthritis occurs in about 30% of those with the skin condition. PsA may also be observed in patients without psoriasis but with a family history positive for psoriasis in first or second-degree relatives.

Psoriasis is a systemic condition with sometimes a profound impact on the quality of the life of patients.

PsA can affect large joints as well as small joints and can also be associated with inflammation in the spine.

The management of PsA has many things in common with the management of rheumatoid arthritis. It is possible that psoriatic arthritis is, in fact, more common than rheumatoid.

Like all autoimmune disorders environmental factors, especially intestinal bacteria, may play a triggering role in the development of PsA. This is currently an intense focus of research.

In psoriatic patients, the immune system is involved in both the skin and the joints. Despite uncertainty about the factor(s) that either initiates or perpetuates this immune reaction, considerable progress has been made in characterising the steps leading to inflammation cascade.

There is now a range of effective lifestyle and pharmacological strategies to block this inflammation.