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RiittaLuosujärvi

Psoriatic Arthritis

Essentials

  • Psoriatic arthritis is a progressive, multiform, chronic, immunological, inflammatory disease of joints and the whole organ system that is often familial and may lead to destruction of joints.
  • Starting treatment without delay may improve the patient's long term prognosis.
  • Treatment aims at reducing the systemic inflammation and at eliminating both skin and joint symptoms.
  • The patient should be motivated for treatment from the very beginning.
  • The treatment of psoriatic arthritis depends on the extent of symptoms, radiological progression, and the activity of the dermatological disease.
  • The treatment of psoriatic arthritis is based on methotrexate and good analgesia.
  • Biological treatment can be used, as necessary.
  • The risk of arterial disease, diabetes and potential depression associated with psoriatic arthritis should always be taken into account when planning the treatment.

Epidemiology

  • The prevalence of cutaneous psoriasis among the European and North-American population is 1.5-3%. In an unselected population, the prevalence of psoriatic arthritis is 0.05-0.25%.
    • At the onset of psoriasis, 2.4% of patients have psoriatic arthritis.
    • The risk of psoriatic arthritis increases with increasing duration of psoriasis, and 5-7% of patients with psoriasis also have arthritis.
    • In severe psoriasis, the risk of arthritis is 40-50%.
  • Psoriatic arthritis may occur without skin symptoms.
  • Psoriatic arthritis of small joints is equally common in men and women but the disease with spondylarthritis is more common in men.
  • The incidence of psoriatic arthritis has increased during the last few decades.
  • People with psoriasis and psoriatic arthritis have many associated disorders, such as cardiovascular disorders, diabetes, IBD and depression. Particular attention should be paid to their treatment.

History, symptoms and findings

  • Susceptibility to the disease is determined by genetic factors.
  • Psoriatic arthritis should be suspected if a patient with cutaneous psoriasis develops symptoms of arthritis and clinical findings consistent with psoriatic arthritis.
    • However, cutaneous psoriasis does not exclude diseases such as rheumatoid arthritis Rheumatoid Arthritis.

Clinical findings typical for psoriatic arthritis

  • Joint symptoms are multiform and often asymmetric.
  • Painful joints and tenderness and inflammation of tendon insertions (enthesitis), such as inflammation in the heel bone at the insertion site of the Achilles tendon commonly occur.
  • Asymmetric inflammation of a few joints is the most common manifestation.
  • Polyarthritis
    • May at first clinically resemble rheumatoid arthritis.
    • Both rheumatoid factor (RF) and serum citrullinated peptide antibodies are usually negative.
  • Inflammation of DIP joints (often PIP + DIP), often associated with typical nail changes ( 1 2 3). It may be very painful.
  • Dactylitis (sausage finger or toe)
  • Asymmetric sacroiliitis and spondylitis are common in patients with spondylarthritis.
  • Typically callus formation on bone surfaces, i.e. in the periosteum
  • Polyarthritic disease eroding bone, and a form of disease causing swelling of the whole limb are rare.
  • Uveitis can be seen in patients with psoriatic arthritis.

Diagnosis

  • The diagnosis is clinical; there are no exact diagnostic criteria.
  • The diagnostic criteria of the CASPAR working group can be used to define the disease. However, it should be remembered that they were made for use in research.
  • Psoriatic arthritis cannot be diagnosed based on laboratory tests.
    • Patients with psoriatic arthritis may have elevated plasma urate levels in the absence of gout.
    • ESR and CRP may be either elevated or normal.
    • Rheumatoid factor and anti-CCP antibodies may be exceptionally elevated.
  • Changes possibly seen in X-ray can be used for diagnosis.
    • Periosteal callus formation
    • Bone erosion
    • Complete fusion of joints
    • 'Pencil-in-cup' changes in small phalangeal joints
    • Unilateral sacroiliitis
    • Asymmetric bulky syndesmophytes, 'jug handles', between vertebrae
    • In the mutilating form of the disease, the middle phalanx, for example, may dissolve completely.
    • Changes in X-rays may appear early.
  • Articular ultrasonography will show thickened synovial membranes with increased blood flow, increased amounts of synovial fluid, increased blood flow in the periosteum, callus formation, erosions and tendonitis.
  • Magnetic resonance imaging (MRI) can be used to confirm vertebral and sacroiliac (SI) joint inflammation before changes can be seen in conventional X-ray. MRI is important also in the assessment of the inflammation and changes in large joints, such as the hip joints. The need for MRI will be defined by a specialist.

Treatment Methotrexate for Psoriatic Arthritis

  • In a fresh psoriatic arthritis, treatment that aims at remission may significantly improve the status of the joints.
  • Traditional synthetic disease-modifying antirheumatic drugs (sDMARD), anti-inflammatory analgesics and biological drugs are used for treatment.
  • Treatment depends on assessment by patient and doctor, the number of inflamed joints, radiological progress and degree of disease of the skin.
  • If, however, there are several symptomatic joints or the disease is progressive, methotrexate, or if it is contraindicated sulphasalazine, is used already at an early stage.
  • A mild psoriatic arthritis is treated with NSAIDs and local intra-articular glucocorticoid injections.
    • If local glucorticoid injections do not suppress the arthritis adequately, the first-line therapy is methotrexate.
  • General remarks
    • Anti-inflammatory analgesics are used particularly in the beginning of the disease; for the form of disease with spondylarthritis and enthesitis, treatment may be needed for several years.
    • Methotrexate is the primary sDMARD for psoriatic arthritis. If methotrexate is contraindicated, sulfasalazine is chosen. Methotrexate often also alleviates cutaneous symptoms.
    • Sudden withdrawal of high-dose systemic glucocorticoids may aggravate cutaneous psoriasis.
    • Ciclosporin is may be effective in the treatment of both skin and joint symptoms, but is is not suitable for long-term treatment.
    • Intra-articular glucocorticoid injections are usually effective.
    • Biological drugs (bDMARD) alleviate both skin and joint inflammation.
  • According to clinical experience, the prognosis of psoriatic arthritis is often better than that of rheumatoid arthritis, and treatment started without delay may predict a milder clinical course.

Treatment chain

  • Patients, whose joint disease is stable, are usually followed-up within primary health care. Also the screening and treatment of associated diseases can be carried out in primary health care.
  • In active and progressive disease, the treatment of psoriatic arthritis is often carried out in cooperation by primary health care, a dermatologist and a rheumatologist.
  • Without consulting a specialist, a physician in primary health care may provide symptomatic treatment and intra-articular glucocorticoid injections for mild psoriatic arthritis.
    • Mild disease usually causes joint pain or rarely inflammation of individual joints.
  • Patients to be referred for an assessment by a rheumatologist include those with fresh polyarthritis (inflammation of more than 4 joints), with a disease that resembles ankylosing spondylitis or with a prolonged inflammation of a few (less than 4) joints that responds poorly to NSAIDs and local glucocorticoid injections or when X-rays show progressive changes.
    • Later on, treatment can usually be provided either entirely in primary health care or the responsibility shared with specialized care.
    • Severe forms of disease are treated in specialized care.
  • Children with psoriatic arthritis should be treated in specialized care.
  • Before pregnancy, a safe pharmacotherapy to be used during pregnacy should be planned and, as required, a rheumatologist consulted.

Follow-up

  • Results of treatment should be followed up and assessed regularly.
  • Full care of the patients should include screening and careful treatment of diseases associated with psoriasis.
  • The medication needs to be monitored by safety tests. See locally available guidance.
  • The special features of biological medicines (bDMARD) should be kept in mind in primary health care, too.
  • Measurement tools are available for following up and assessing response to treatment.
    • In the peripheral form of disease, response to treatment can be assessed using indicators used for the follow-up and assessment of response to treatment in patients with rheumatoid arthritis (DAS28, ACR response, HAQ, VAS)
    • The form of disease with spondylarthritis can be monitored using indicators of response to the treatment of ankylosing spondylitis (BASFI, BASDAI, VAS).
    • In patients with enthesitis, response to treatment can be assessed using VAS and MASES indicators.

References

  • Gelfand JM, Gladman DD, Mease PJ et al. Epidemiology of psoriatic arthritis in the population of the United States. J Am Acad Dermatol 2005;53(4):573. [PubMed]
  • Kaipiainen-Seppänen O. Incidence of psoriatic arthritis in Finland. Br J Rheumatol 1996;35(12):1289-91. [PubMed].
  • Wilson FC, Icen M, Crowson CS et al. Incidence and clinical predictors of psoriatic arthritis in patients with psoriasis: a population-based study. Arthritis Rheum 2009;61(2):233-9. [PubMed]
  • Prey S, Paul C, Bronsard V et al. Assessment of risk of psoriatic arthritis in patients with plaque psoriasis: a systematic review of the literature. J Eur Acad Dermatol Venereol 2010;24 Suppl 2():31-5. [PubMed]
  • Christophers E, Barker JN, Griffiths CE et al. The risk of psoriatic arthritis remains constant following initial diagnosis of psoriasis among patients seen in European dermatology clinics. J Eur Acad Dermatol Venereol 2010;24(5):548-54. [PubMed]
  • Gladman DD, Shuckett R, Russell ML et al. Psoriatic arthritis (PSA)--an analysis of 220 patients. Q J Med 1987;62(238):127-41. [PubMed]
  • Huerta C, Rivero E, Rodríguez LA. Incidence and risk factors for psoriasis in the general population. Arch Dermatol 2007;143(12):1559-65. [PubMed]
  • Icen M, Crowson CS, McEvoy MT et al. Trends in incidence of adult-onset psoriasis over three decades: a population-based study. J Am Acad Dermatol 2009;60(3):394-401. [PubMed]
  • Mehta NN, Azfar RS, Shin DB et al. Patients with severe psoriasis are at increased risk of cardiovascular mortality: cohort study using the General Practice Research Database. Eur Heart J 2010;31(8):1000-6. [PubMed]
  • Mease PJ, Antoni CE, Gladman DD et al. Psoriatic arthritis assessment tools in clinical trials. Ann Rheum Dis 2005;64 Suppl 2():ii49-54. [PubMed]
  • Taylor W, Gladman D, Helliwell P et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum 2006;54(8):2665-73. [PubMed]
  • Kane D. The role of ultrasound in the diagnosis and management of psoriatic arthritis. Curr Rheumatol Rep 2005;7(4):319-24. [PubMed]
  • Rook´s Textbook of Dermatology. Burns DA, Breathnach SM, Cox N, Griffiths CE (toim.). Blackwell Publishing 2004.
  • Griffiths CE, Dubertret L, Ellis CN et al. Ciclosporin in psoriasis clinical practice: an international consensus statement. Br J Dermatol 2004;150 Suppl 67():11-23. [PubMed]
  • Ogdie A, Weiss P. The Epidemiology of Psoriatic Arthritis. Rheum Dis Clin North Am 2015;41(4):545-68. [PubMed]

Evidence Summaries ⬆