It's important that psoriatic arthritis is diagnosed early so treatment can be started as soon as possible.
There's no specific test for psoriatic arthritis, but the diagnosis is based on your symptoms and a physical examination. Your doctor will check for psoriasis and may ask if there's a history of psoriasis or psoriatic arthritis in your family.
People with psoriasis may be regularly asked about joint symptoms by their GP and/or dermatologist.
If several joints are affected, your doctor will consider features such as the pattern of arthritis – that is, which joints are affected.
It can be difficult to tell the difference between psoriatic arthritis and rheumatoid arthritis, but blood tests such as those for rheumatoid factor and anti-CCP antibody can help.
Psoriatic arthritis can have similar symptoms to gout, so x-rays of your back, hands and feet may also be helpful, as psoriatic arthritis can affect the bones and joints in these areas in a different way to other conditions.
Other types of imaging, such as MRI and ultrasound scans, may help to confirm the diagnosis.
The National Institute for Health and Care Excellence (NICE) published new quality standards in 2013 to help improve the care of people across England with psoriasis.
The standards are mainly aimed at GPs and state that people with psoriasis should be offered an appointment every year to check for signs of psoriatic arthritis and every five years to check their cardiovascular health. This should help in diagnosing psoriatic arthritis as early as possible and making sure that the right treatment is started.