Psoriatic arthritis is a chronic inflammatory seronegative spondyloarthropathy associated with psoriasis
May develop in 6-41% of patients with psoriasis
Usually develops after an average of 10 years of cutaneous manifestations
Dermatologists are encouraged to monitor for signs and symptoms of psoriatic arthritis every visit
All patients suspected of having psoriatic arthritis should be assessed by a rheumatologist so that an early diagnosis can be made and joint damage can be reduced
Prevalence in the general population ranges from 0.1%-1%
Can develop at any time including childhood but most often occurs between 30-50 years old
Affects men and women equally
Peripheral arthritis is more common in women and axial disease is more common in men
Women have less radiographic progression but with worse pain, function and fatigue outcomes compared to men
Signs and Symptoms
Signs and symptoms include:
Peripheral joint pain, stiffness and swelling (in arms and legs including elbows, wrists, hands and feet)
Axial joint pain, stiffness and swelling (in shoulders, spine and hips)
Tenderness of the joint and surrounding ligaments and tendons
Presence of skin and nail lesions
Enthesitis, tenosynovitis and dactylitis
Extra-articular manifestations (ie uveitis)
Symptoms range from mild to very severe
Severity of the skin disease and the arthritis do not correlate with each other
Nail disease is commonly found in patients with psoriatic arthritis especially those with distal interphalangeal joint involvement
Patients with axial involvement tend to have earlier onset of arthritis, more severe nail onycholysis, symptoms of inflammatory back pain and inflammatory bowel disease (IBD)
Psoriatic arthritis may start slowly with mild symptoms or may be preceded by a joint injury
Pathogenesis
Results from an interplay of genetic predisposition, environmental triggers (eg biomechanical stress, infections, smoking, obesity), local factors according to disease site (joints, skin, spine, entheses), and interaction with innate and adaptive immune responses
Immune system activation leads to the development of synovitis, enthesitis, erosions, and lesions in the articular cartilage and skin
