Understanding Psoriatic Arthritis

(Part I)

This week we start discussing another disorder which is called psoriatic arthritis.

Psoriatic arthritis (PsA) is a health condition with heterogeneous manifestations in patients who have been suffering or having latent psoriasis. It comprises both musculoskeletal as well as non-musculoskeletal issues; the latter particularly include the skin and the nails, but also potentially the gut (inflammatory bowel disease) or the eyes (uveitis). 

Active chronic PsA may be associated with cardiovascular, psychological and metabolic comorbidities, which, together with the musculoskeletal features, may lead to a significant patient suffering with impact on quality of life and may lead to premature death.

The daily management of patients with PsA includes non-pharmacological as well as pharmacological treatments. The number of disease-modifying anti-rheumatic drugs (DMARDs) indicated for PsA has multiplied in the last 10 years. The usual treatments include not only conventional synthetic DMARDs (csDMARDs) such as methotrexate (MTX), sulfasalazine and leflunomide and tumour necrosis factor inhibitors (TNFi), but also other targeted biological agents (bDMARDs) aimed at different cytokines, such as TNF, interleukin (IL)-12/23 and IL-17A, as well as targeted synthetic DMARDs (tsDMARDs) that inhibit phosphodiesterase-4 (PDE4) or Janus kinases (JAKs).

These multiple newer medications have been seen to work well in short-term of time based on randomised controlled trials using placebo as comparator for drug approval. However, research involving the comparison of different drugs, is rather limited and doctors need to be guided in making treatment decisions.

The European League Against Rheumatism (EULAR) developed recommendations for the pharmacological management of PsA in 2011 and updated them in 2015. These recommendations focuses mainly on the musculoskeletal aspects of the disease and addressed the entire array of PsA severity as they are related to patients with very mild to very severe PsA.

There was a need to have a guideline update of the 2015 recommendations in order to accommodate newly obtained pieces of evidence. 

Next week, we will be making a deep dive into the nature of this disease and throughout the series we will also tackle the different treatment modalities.