ISTOCK.COM / LIPOWSKI Health All about... Psoriasis is a common skin condition but what is psoriatic arthritis? psoriatic WORDS: DR SARAH JARVIS A arthritis sk the average person about types of arthritis, and theres a good chance theyll be able to name osteoarthritis the most common, non-inflammatory type, which affects about 8.75 million people in the UK aged over 45. They may have heard of rheumatoid arthritis, which affects more than 400,000 people in the UK. But many wont have heard of psoriatic arthritis, despite the fact that about one in five people with psoriasis develops this condition. Psoriasis is a skin condition and the most common features are plaques patches of skin overlaid with silvery scales. Skin is constantly being produced from a base layer and shed from the surface, a process that usually takes about 28 days. In psoriasis, the process is hugely accelerated, with the immune system attacking the skin. Signs and symptoms Psoriasis is thought to be an autoimmune condition, like rheumatoid arthritis, which often runs in families. It most often starts in those aged 15 to 30, with psoriatic arthritis commonly developing between the ages of 25 and 50. However, both conditions can start at any age. In about one in five cases, joint problems are diagnosed before any obvious signs of psoriasis. Women with psoriatic arthritis are more likely to show a rheumatoid pattern of joint involvement especially wrists, hands, feet and ankles on both sides. Unlike rheumatoid arthritis, it tends to affect the finger joints further from the knuckle, rather than those closest to the knuckle joints. Men are more likely to have a spondylitic pattern of joint inflammation, affecting the spine and sacroiliac joints, with morning stiffness and limited back movement. Others may have an asymmetrical pattern, affecting one or just a few joints on one side. It often affects one large joint such as a hip or knee, along with a few small joints in hands or feet. Psoriatic arthritis causes inflammation of the synovium, which is the tissue that surrounds joints. It can sometimes also affect the tendons joining muscle to bone and the tough ligaments that stabilise the joints. Symptoms include pain and stiffness, which is often worse after resting or sleeping; red, hot joints; swelling; and sometimes permanent joint damage. Getting help Early diagnosis is important, as prompt treatment with disease modifying anti-rheumatic drugs (DMARDs) can slow down the progression of the condition. They also reduce joint problems. DMARDs take up to six months to work properly, so are used with treatments that help to relieve symptoms. The most common group of symptom-relieving drugs used are non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen. These reduce inflammation as well as pain, but can cause stomach inflammation and kidney damage at high doses. They may also lead to flare-ups of the skin symptoms of psoriasis, so talk to your doctor if your psoriasis is getting worse. Alternative painkillers, such as paracetamol or codeine, may be recommended. Steroid injections may also be suitable for badly inflamedjoints. Staying active is crucial to keeping your muscles strong. A physiotherapist may be able to suggest some exercises that will retain your strength and flexibility ask your GP for details. n Read more at versusarthritis.org/psoriatic-arthritis