Psoriatic Arthritis

Psoriatic arthritis (PsA) (synonyms: Arthritis mutilans psoriatica; Arthritis psoriatica; Arthritis psoriatrica; Arthritis and spondylitis in psoriasis; Arthropathia psoriatica; Arthropathia psoriatica n.e.c. ; Arthropathy in psoriasis n.e.c. ; distal interphalangeal psoriatic arthropathy; joint psoriasis; juvenile arthritis in psoriasis; osteoarthropathia psoriatica; psoriasis arthropathica; psoriatic arthropathy; psoriatic osteoarthropathy; spondylitis psoriatica; psoriatic arthritis; ICD-10 L40. 5: Psoriatic arthropathy) describes the occurrence of arthritis (inflammatory joint disease) in patients who have psoriasis. Typical skin lesions are irregularly circumscribed inflammatory and scaly papules/nodules that occur predominantly on the knees, elbows, and scalp. Joint inflammation predominantly affects the hands and feet (peripheral joints) and/or the spine (spondylitis/inflammation of the vertebral joints).The disease belongs to the group of predominant peripheral spondyloarthritides (SpA, pSpA). Furthermore, it belongs to the group of seronegative spondyloarthritides (synonym: seronegative spondyloarthropathy), in which inflammation of the small vertebral joints (spondylarthritis) is present. These diseases are distinguished from rheumatoid arthritis (chronic polyarthritis) by the absence of rheumatoid factors (= seronegative). Psoriatic arthritis can be divided into the following forms on the basis of symptoms:

  • Peripheral type (most common form) – finger or foot joints are affected:
    • Asymmetric oligoarthritis (≤ 4 joints) (60% of cases).
      • Mostly affects the small joints
      • “Ray infestation” with single fingers (“sausage fingers”) – arthralgia (joint pain) and joint swelling of all 3 joints of a finger
      • Often HLA-B27 positive
    • Symmetrical polyarthritis (20% of cases).
      • Small and large joints are affected
      • Similar to rheumatoid arthritis
      • May be rheumatoid factor positive
    • Distal-transverse end joint involvement (synonyms: distal interphalangeal dominant arthritis; DIP synovitis) (5% of cases).
      • Almost always occurring psoriatic changes of the involved nails
      • Similar to Heberden’s arthrosis
    • mutilating, ankylosing (5% of cases) – arthritis mutilans.
      • Severe osteolytic destruction (destruction) of individual fingers or toes.
      • Possibly telescopic finger (finger appears massively shortened, can be restored to original size by traction)
  • Spine type – spondyarthritis (synonyms: spondylarthritis, spondyloarthritis) (10% of cases).
    • Affects mainly cervical spine (cervical spine) and sacroiliac joints (connect the sacrum (spine) and ilium (pelvis) together)
    • Symptoms as in ankylosing spondylitis – chronic inflammatory disease of the spine that can lead to joint stiffness (ankylosis) of the affected joints. The sacroiliac joints (ISG; sacroiliac joints) are typically affected first.
    • Mostly asymmetric affection
    • HLA-B27 positive
  • Mixed type
  • Special form – psoriasis pustulosa palmoplantaris (psoriasis of the palms and soles) with sternoclavicular joint hyperostosis (bone hypertrophy of the sternoclavicular joint).

In adolescents, the association of psoriasis and arthritis is called juvenile psoriatic arthritis (JPsA). Often, JPsA precedes the actual skin disease. Peak incidence: Psoriatic arthritis (PsA) occurs predominantly between the ages of 30 and 50. Psoriatic arthritis (PsA) affects approximately 5-15% of psoriasis patients. Approximately 66% of psoriatic arthritis patients have nail psoriasis. Frequently, the scalp is also affected. The prevalence (disease frequency) is 0.1-0.2 % in Germany. Course and prognosis: Arthritic symptoms usually occur a few years (up to 10 years) after the skin changes (in about 75% of cases), rarely before. If the joint affection occurs before the skin changes, it is called “psoriatic arthritis sine psoriase”.Psoriatic arthritis is characterized by a highly chronic course with relapses and remissions (regressions). The disease activity of skin psoriasis and arthritis does not usually run in parallel.However, therapy of the skin psoriasis can also lead to an improvement in arthritis symptoms.Psoriatic arthritis is treatable, but not curable. Patients with pronounced psoriasis have an increased risk of cardiovascular diseases, so that appropriate preventive examinations should be carried out. Comorbidities (concomitant disease): psoriatic arthritis is associated with a 2.5-fold increased risk of uveitis (inflammation of the medial eye skin), while mild as well as severe psoriasis is associated with a 40% increased risk of uveitis.