Psoriatic arthritis

1.
Vitebsk State Order of Peoples’ Friendship Medical
University
Department of Facultative Therapy
Head of Department:​ ​В.И. Козловский
Teacher: ​Л.В. Бабенкова
Report: Psoriatic Arthritis
Dinoosh De Livera
Group 53, 6th Course
Overseas Students Training Faculty
2018

2. 1
Definition:
Chronic disease characterized by a form of inflammation of the skin (psoriasis) and
joints (inflammatory arthritis).
❏ Inflammatory arthritis associated with psoriasis.
❏ Seronegative oligoarthritis.
❏ Usually seronegative for Rheumatoid Factor and cyclic citrullinated peptides (CCP).
❏ Classified with HLA-B27-associated spondyloarthropathies.
❏ 15%-25% of people with psoriasis develop psoriatic arthritis.

3. 2
Causes:
Currently unknown (Idiopathic).
A combination of : -
a) Genetic factors : HLA-B27 is found in more than 50% of psa patients.
b) Immune factors : Stressors or changes in the immune system may affect the
development or progression of the disease - environmental factors.
c) Environmental factors.
Risk Factors:
❏ The major risk factor is having a family member with psoriasis 40%.
❏ About 15% of people with psoriasis will develop psoriatic arthritis.
❏ equally common in men and women.
Epidemiology:
❏ Likely in up to 25-34% of patients with presence of skin disease.
❏ Overall prevalence 0.04-1.2%.
❏ M=F although it differs in subsets.
❏ Peak age of onset between 30-55 years.
CASPAR criteria
1) Evidence of psoriasis:
a) current - 2
b) history of - 1
c) family history of - 1
2) Psoriatic nail dystrophy (onycholysis, pitting, hyperkeratosis).
3) Negative rheumatoid factor (RF -).
4) Dactylitis, either current or history of.
5) Radiological evidence of juxta-articular new bone formation.

4. 3
Subtypes:
1) DIP joint pattern
2) Oligoarticular (<5 joints) pattern, usually asymmetric
3) Polyarticular (>=5 joints), symmetric in half
4) Arthritis mutilans
5) Spondyloarthritis
Other Rheumatological Findings:
❏ Enthesitis (inflammation at site of tendon insertion).
❏ Tenosynovitis (inflammation of tendon and its enveloping sheath).
❏ Dactylitis or “sausage digit”.
Extra-articular findings:
❏ Skin - psoriasis
❏ Nails - pits and onycholysis
❏ Pitting edema - often asymmetrical
❏ Ocular inflammation - conjunctivitis, iritis

5. 4
Diagnosis those without skin findings:
❏ look for distal joint involvement in asymmetric distribution
❏ look at the nails
❏ look in ears
❏ ask about family history
❏ Dactylitis

6. 5
Diagnostic testing:
1) No diagnostic laboratory testing
2) By definition, psoriatic arthritis is classified as a “seronegative” arthritis, meaning that
the rheumatoid factor is typically negative
3) However, low titer rheumatoid factor can be detected in 5% to 9% and Anti-CCP in 5%
of psoriatic arthritis patients. This can make it difficult to separate from coexistent
rheumatoid arthritis.
4) However, the presence of DIP involvement, enthesitis, and dactylitis supports a diagnosis
of psoriatic arthritis regardless of the serologies.
5) ANA are reported in 10% to 15%.
6) ESR , CRP and anemia may vary with disease activity.
7) Patients with an elevated ESR and CRP are more likely to have polyarticular disease and
a worse prognosis.
8) Hyperuricemia is seen in 20% and related to the increased incidence of the metabolic
syndrome seen in patients with psoriatic disease.
9) Analysis of synovial fluid reveals inflammatory fluid with a neutrophilic predominance.
10) Synovial fluid analysis reveals inflammatory fluid, with white blood cell counts usually
in the 5000–50,000/mcL range.
11) Radiologically:
a) erosive changes and new bone formation in distal joints
b) lysis of terminal phalanges
c) fluffy periostitis and new bone formation at sites of enthesitis
d) “pencil in cup” appearance
Differential Diagnosis:
1) Reactive (Reiter’s) Arthritis.
2) Rheumatoid Arthritis with concomitant psoriasis.
3) Ankylosing spondylitis.
4) Gouty arthritis.

7. 6
Treatment​:
1) NSAIDs if disease is mild.
2) PT, OT, splinting devices.
3) Local steroid injection
4) If erosive disease, treat aggressively with DMARDs (Methotrexate, sulfasalazine,
leflunomide, and cyclosporine).
a) Apremilast is a tsDMARD acting as a PDE4-inhibitor and has been demonstrated
to be efficacious in PsA.
5) Anti-TNF (Etanercept, Infliximab, Adalimumab, Golimumab, & Certolizumab Pegol):
a) 1st choice as well established efficacy/safety balance in PsA
b) Ustekinumab is a fully human IgG1κ monoclonal antibody that binds to the
common p40 subunit shared by IL-12 and23.
c) Secukinumab is a fully human, high affinity, anti-IL-17A monoclonal antibody
that binds to and neutralizes IL-17A
d) Both may be useful but are recommended here only as alternatives, especially if
TNFis fail or cannot be applied
6) If skin disease is the major issue, should be managed by a dermatologist.
7) Early referral to rheumatology for initiation of DMARDs to prevent progression.
8) Demonstrated efficacy in PsA, for skin and joint involvement, as well as in preventing
radiographic damage

8. 7
General points & factoids:
● How prevalent is psoriasis and psoriatic arthritis in the general population?
○ Epidemiologic studies suggest that the prevalence of psoriasis is approximately
2% to 3%. Whites are affected (two times) more often than other ethnic groups.
○ The estimates of inflammatory arthritis accompanying psoriasis range from 7%
to 42% (average 26%).
○ prevalence of arthritis is relatively equal between the sexes. However, in patients
with spinal involvement, the male to female ratio is almost 3:1 .
○ Men also tend to have a higher prevalence of DIP-only involvement, whereas
women tend to have a higher prevalence of symmetric polyarthritis.
○ Most patients present between the ages of 35 and 50 years. However, juvenile
psoriatic arthritis is also well recognized and usually presents between ages 9 and
12 years.
● Is there a relationship between the onset of psoriasis and the onset of
arthritis?
○ Psoriasis precedes arthritis by an average of 8 to 10 years in 67% of patients.
○ Arthritis precedes psoriasis or occurs simultaneously in 33% of patients,
particularly in childhood and in older patients (>age 50 years).
● Is there a relationship between the onset of psoriasis and the onset of
arthritis?
○ Psoriasis precedes arthritis by an average of 8 to 10 years in 67% of patients.
○ Arthritis precedes psoriasis or occurs simultaneously in 33% of patients,
particularly in childhood and in older patients (>age 50 years).

9. 8
● What are the current classification criteria for psoriatic arthritis?
○ The CASPAR (Classification of Psoriatic Arthritis) criteria are:
■ 1. Evidence of psoriasis (current, past, family): two points if current
history of psoriasis, one point others.
■ 2. Psoriatic nail dystrophy: one point
■ 3. Negative rheumatoid factor: one point.
■ 4. Dactylitis (current, past history): one point.
■ 5. Radiographic evidence of juxtaarticular new bone formation: one point.
Three or more points have 99% specificity and 92% sensitivity for diagnosis of psoriatic arthritis
● Dactylitis “sausage digit”:
○ The complete swelling of a single digit of the hand or foot.
○ A distinctive feature of the spondyloarthropathies, and it is common in psoriatic
arthritis, occurring in 30-50% of patients at some point during the course of the
disease.
○ Toes are more frequently involved than fingers.
● Skin changes:
○ Enthesitis Inflammatory process occurring at the site of insertion of tendons into
bone up to 40% of psoriatic arthritis patients.
○ On examination, there is a soft tissue swelling & tenderness to palpation & may
overlying erythema and warmth.
○ Common sites for enthesitis:Achilles tendon, plantar fascia, and pelvic bones.
Entheseal inflammation may evolve to destruction of the adjacent bone and joints.

10. 9
● Nail involvement:
○ Common Psoriatic nail changes include ridging, pitting, onycholysis, and
hyperkeratosis.
○ May represent the manifestation of psoriasis before the presence of more
characteristic skin lesions.
○ Nail changes on the affected finger virtually always occur when psoriatic arthritis
affects a DIP joint.
● Spondyloarthropathy:
○ Symptomatic involvement of the sacroiliac joints and axial skeleton is less
common than peripheral joints.
○ Sacroiliitis usually unilateral & presents with pain and stiffness in the lower back
or buttock.
○ Tenderness can sometimes be elicited by direct compression test on SIJ or
Gaenslen test.
● Extraarticular manifestations:
○ Eye disease includes conjunctivitis in 20% and acute iritis in over 7% of cases.
Iritis can be bilateral and is more commonly associated with axial involvement.
○ Other less common features include oral ulcers, urethritis, nonspecific colitis, and
rarely dilatation of base of aortic arch causing aortic insufficiency.
● Can laboratory tests help in diagnosing psoriatic arthritis?
○ By definition, psoriatic arthritis is classified as a “seronegative” arthritis, meaning
that the rheumatoid factor is typically negative
○ However, low titer rheumatoid factor can be detected in 5% to 9% and Anti-CCP
in 5% of psoriatic arthritis patients. This can make it difficult to separate from
coexistent rheumatoid arthritis.
○ However, the presence of DIP involvement, enthesitis, and dactylitis supports a
diagnosis of psoriatic arthritis regardless of the serologies.
○ ANA are reported in 10% to 15%.
○ ESR , CRP and anemia may vary with disease activity.
○ Patients with an elevated ESR and CRP are more likely to have polyarticular
disease and a worse prognosis.

11. 10
○ Hyperuricemia is seen in 20% and related to the increased incidence of the
metabolic syndrome seen in patients with psoriatic disease.
○ Analysis of synovial fluid reveals inflammatory fluid with a neutrophilic
predominance.
○ Synovial fluid analysis reveals inflammatory fluid, with white blood cell counts
usually in the 5000–50,000/mcL range.
● What radiographic features help to differentiate psoriatic arthritis from other
inflammatory diseases?
○ Overall, 45% to 50% of patients will develop erosions within the first 2 years of
their disease and eventually 67% will develop radiographic changes:
■ Asymmetric involvement.
■ Relative absence of juxtaarticular osteopenia.
■ Involvement of DIP joints.
■ Erosion of the terminal tufts (acroosteolysis).
■ Whittling of the phalanges.
■ Cupping of the proximal portion of the phalanges (pencil-in-cup
deformity).
■ Bony ankylosis distal to metacarpophalangeal (MCP) joints.
■ Osteolysis of bones (arthritis mutilans).
■ Polyarticular unidigit—MCP,(PIP), and DIP of same finger involved.
■ Sacroiliac and spondylitic changes (usually asymmetric).

12. 11
Course and Prognosis:
❏ 20% of patients have a severe an debilitating form of arthritis.
❏ Originally thought to be more benign course than RhA
❏ Progression of clinical damage occurs in a majority of patients.
❏ Radiologic changes occur over time despite treatment.
References:
1) https://radiopaedia.org/articles/psoriatic-arthritis
2) www.papaa.org
3) https://www.mayoclinic.org/diseases-conditions/psoriatic-arthritis/.../syc-20354076
4) https://www.medicinenet.com/psoriatic_arthritis/article.htm
5) www.arthritis.org › About Arthritis › Types › Psoriatic Arthritis
6) www.arthritisresearchuk.org/arthritis-information/conditions/psoriatic-arthritis.aspx
7) https://www.nhs.uk/conditions/psoriatic-arthritis/
8) www.google.com/images/psoriatic-arthritis
9) Oxford Handbook of Clinical Medicine - 9th Edition - Psoriatic arthritis
10) Harrison’s Manual of Medicine - 16th Edition - Psoriatic arthritis
11) Kumar & Clark’s Clinical Medicine - 7th Edition - Psoriatic arthritis