Arthritis associated with Psoriasis

Arthritis associated with Psoriasis

Psoriatic arthritis affects 5-40% of the 1-3% of people with skin psoriasis.  The most common age at onset is 20 to 40 years.  Men and women are equally affected.  The cause is partly genetic.

Psoriasis usually precedes the arthritis, but in 10% the arthritis is the first problem encountered.  80% of patients with arthritis have nail deformities, compared to 20% of patients with “uncomplicated” psoriasis.

The pattern of joints involved varies, from the spine, to a presentation more typical of rheumatoid arthritis with hands and feet affected.  There is a particular predeliction for the end finger joint next to the nail, and for involvement of a whole finger, including tendons and other tissues, known as “dactylitis”.

X-Rays show a characteristic type of arthritis

Treatment

Skin therapy has no effect on arthritis.  Treatment options include anti-inflammatories (NSAIDs), Disease Modifying Drugs (sulphasalazine, methotrexate, cyclosporin) and steroid injections into joints or around tendons,

Surgical options are similar to those described for rheumatoid arthritis.  In particular, fusion of the end finger joint with a screw is easily performed under local anaesthetic.