Psoriatic Arthritis

Psoriatic arthritis (PsA) is a diverse, sometimes subtle and frequently overlooked type of arthritis. Psoriasis occurs in up to 3% of the population many of whom do have either musculoskeletal problems linked to psoriasis or the associated arthritis. However, many people with PsA don't have psoriasis because psoriasis is just one manifestation of a single condition that can cause bone, joint, tendon, nail, skin and gut symptoms. It gets more complicated though! Not everyone has all these components when they get the condition and sometimes any number of these features can come and go over a period of years. For instance, someone can have psoriasis in their 20s, then it resolves not to occur again but they develop PsA in their 40s without developing psoriasis again.

And (even more confusing) some people with PsA don't have arthritis! 'Arthritis' means joint disease/inflammation. However, the painful and stiff symptoms in PsA are often due to problems - primarily inflammation-based lesions - occurring in a bone, tendon or an enthesis, not a joint. An enthesis is the part of a tendon or ligament which attaches to a bone. The Achilles' tendon at the back of your heel, fans out and attaches at a broad flat enthesis - and 'yes' Achilles' tendonitis (/enthesitis) can be part of PsA. Other entheses typically affected in PsA include at the base of the heel (plantar fascia), elbows (often misdiagnosed as 'tennis elbow'), around the front of the knees or side of the hips (greater trochanter) and in the back and neck.

Enthesitis-predominant PsA is also often misdiagnosed as 'Fibromyalgia' and often, where enthesitis only affects one place at a time, it is often diagnosed as something else and the opportunity to diagnose the parent condition PsA is missed.

The following treatments can help PsA: steroid injections, non-steroidal anti-inflammatory painkillers (NSAIDs), methotrexate, leflunomide, ciclosporin, TNF inhibitors (e.g. adalimumab), ustekinumab, apremilast, secukinumab (type the name of the drug in the search box at: www.medicines.org.uk and read the relevant PILs document)

Links:
Information on the condition and link to its treatments: 
www.versusarthritis.org/about-arthritis/

A principle source of advice, support and information on PsA:
www.papaa.org