Table 1

Summary of key differences in PsA and RA

Psoriatic arthritisRheumatoid arthritis
Clinical/anatomical▸ DIP joint and axial arthritis
▸ Often asymmetrical
▸ Enthesitis common
▸ MCP and wrist joints
▸ Predominantly symmetrical
Genetic▸ HLA Cw6 and B27
▸ IL23 receptor
Pathogenesis▸ Absence of circulating autoantibodies
▸ Distinct vascular pathology
▸ T-lymphocyte predominance
▸ Early expression of vascular growth factors
▸ Circulating autoantibodies RF/ACPA
▸ T-lymphocyte and B-lymphocyte infiltrate
▸ Late expression of vascular growth factors
Response to therapy▸ DMARDs, eg, methotrexate
▸ TNF inhibitors
▸ Abatacept
▸ Ustekinumab
▸ Secukinumab
▸ DMARDs, eg, methotrexate
▸ TNF inhibitors
▸ Abatacept
▸ Rituximab
▸ Tocilizumab
  • ACPA, anticitrullinated protein antibodies; DIP, distal interphalangeal; DMARDs, disease modifying anti-rheumatic drugs; HLA, human leucocyte antigen; IL, interleukin; MCP, metacarpophalangeal; RF, rheumatoid factor; TNF, tumour necrosis factor.