Psoriatic arthritis with the development of secondary Osteoarthritis

History and Examination

The patient was a 65 year old female.

She had a history of multiple swollen joints spanning back 20 years.

She initially responded well to Methotrexate and non steroidal anti-inflammatory drugs.

In the previous year she stopped Methotrexate as it "lost effectiveness". Since stopping the drug she felt no worse.

She was complaining of constant pains around her chest, hands, back, feet and knees.

Her sleep was poor but she did not have significant morning stiffness of her joints.

On examination she was overweight.

She had carpo metacarpal joint (CMC) osteoarthritic change. There was no synovitis (joint swelling) or nail changes. There was no evidence for enthesopathy.

She had quite a marked bony thickening over her sternoclavicular joint (top of breastbone) but this was not tender.

There was global restriction of movement in the spine. She has minimal Osteoarthritic changes in the knees and big toe.

Key Messages

Some of the bony changes including those of the sternum or breast bone could be secondary to previous bouts of Psoriatic Arthritis.

Other features that support more of a degenerative or osteoarthritic process was the pattern of pain (constant rather than being worse in morning), lack of swelling and non response to treatments for inflammation.

The key message here is that the active Psoriatic Arthritis phase of disease had passed and her ongoing joint symptoms were due to Osteoarthritis or "wear and tear" and biomechanical related factors including her weight.

The physician must recognise this and might be able to discontinue drugs like Methotrexate for this late stage of disease.

The patients was warned about the risk of a flare of the Psoriatic Arthritis.

The treatment in this particular case included attempted weight reduction, physiotherapy and pain killers.

To summarise, it is important to determine what is the main cause of pain in patients with chronic Psoriatic Arthritis. Since Psoriatic Arthritis and some types of Osteoarthritis afflict the enthesis and bone, it can be hard to tell them apart.