Psoriatic Arthritis/Ankylosing Spondylitis

Question 1

Psoriatic Arthritis

General

Answer 1

Seronegative spondyloarthropathy and chronic, progressive inflammatory arthritis
Develops in ~15-30% of patients with psoriasis (cutaneous or nail involvement)
Usually develops after age 30
♂=♀

Question 2

PA

Pathogenesis/gene

Answer 2

Not completely understood
HLA-B27 positivity in many patients
T-cell mediated attack on the joints

Question 3

PA

S/Sx

Answer 3

Cutaneous psoriasis: erythematous plaques with overlying silvery scales
Nail pitting, thickening, or onycholysis
Joint pain
Symmetric or asymmetric arthritis
Distal interphalangeal (DIP) joints of finger and toes
Sacroiliac joints
Spine (neck and low back)
Morning joint stiffness - mimics RA

Enthesitis - inflammation at the site of tendon insertion
Tenosynovitis - inflammation of the fluid-filled sheath surrounding a tendon
Dactylitis - “sausage digits”
Arthritis mutilans – severe form that causes destruction of multiple hand joints with telescoping

Oligoarticular - < 3 joints
Polyarticular - > 5 joints

Question 4

PA

Dx

Answer 4

Labs:
Negative for anticyclic citrullinated peptide antibodies and anti-nuclear antibodies

Plain-film radiographs: best initial test

DIP arthritis:
Resembles severe OA on PE; “pencil-in-cup” deformity

Arthritis mutilans:
Telescoping digits
Sacroiliitis

Arthritis mutilans

Question 5

PA

Tx

Answer 5

Goal of treatment is to control skin/nail lesions and reduce joint inflammation

Pain
NSAIDs

Disease-modifying antirheumatic drugs (DMARDs) for mild to moderate disease
Methotrexate
Sulfasalazine

Biologic therapy for moderate to severe disease
TNF-alpha blockers: infliximab, etanercept, and adalimumab
IL12/IL23 inhibitor: ustekinumab

Question 6

PA

Question 7

Ankylosing Spondylitis

General

Answer 7

Seronegative spondyloarthropathy characterized by chronic inflammation of the axial skeleton
Epidemiology:
Age at onset: 20–30 years
3 times more common in men
10–20 times more common in 1st-degree relatives of those with ankylosing spondylitis

Etiology:
Exact cause unknown
Strong association with HLA-B27

Question 8

AS

Patho

Answer 8

Chronic inflammation of the ligaments and theannulus fibrosusof theintervertebral disc → erosion of boneand destruction of articular tissues
Erosion→fibrocartilageregeneration →fibrosisandossification→ syndesmophyte formation
Syndesmophytes bridge together → vertebral fusion

Question 9

AS

Articular manifestations

Answer 9

Pain:
Lower back andneck
Buttock (SI joint involvement)
Progressive
Often nocturnal
Varies in intensity
Present for > 3 months
Paraspinal muscle spasm

Morning stiffness:
Improves with activity or exercise
Worsened by inactivity
Diminishedrange of motion of thespine

Oligoarthritis (50% ofpatients):
Asymmetrical involvement of ≤ 4 peripheral joints
Pain, warmth,swelling, and stiffness
Consider concomitant psoriatic arthritis

AS is considered “axial” and PsA is considered “peripheral” in reality,symptoms can overlap
Patient can also have cardiac, pulmonary, and GI symptoms

Question 10

AS

Extra-articular manifestations

Answer 10

General:
Fatigue
Weakness
Low-grade fever
Weight loss

Ocular:
Anterioruveitis – eye pain and photophobia

Question 11

AS

Spine PE

Answer 11

Spine:
Cervical and upperthoracic vertebrae:
Accentuated thoracickyphosis
Stooped, forward-flexed position (when fused)
Distance between the chin and sternum with flexed head > 2 cm
Lumbar vertebrae:
Reducedrange of motion (Schober’s test)
Loss of lumbar lordosis

Schober Test for Lumbar Spine Flexion: https://youtu.be/eYOUA9asDu8

Question 12

AS

Sacroiliac joint PE
Specific tests

Answer 12

Localized tenderness
Mennell’s sign
3 phase hyperextension test used to differentiate whether pathology is in the lumbar spine, the sacroiliac joint, or the hip joint

Patrick test (FABER)
Used to diagnose pathologies at the hip, lumbar spine, and sacroiliac joint
Flexion, ABduction, External Rotation or figure 4 test
Test is positive if it reproducespainin the ipsilateralsacroiliac joint

Question 13

AS

Answer 13

Question 14

Answer 14

Question 15

AS

Tenderness at the following points:

Answer 15

Achilles tendon insertion
Insertion of theplantar fascia on thecalcaneusor the metatarsal heads
Base of the 5th metatarsal head
Tibial tuberosity
Superior and inferior poles of thepatella
Iliac crest

Question 16

AS

Image findings
SI/spine findings

Answer 16

Plain-film radiographs:
Diagnostic and assesses severity of the disease

Bilateral sacroiliitis:
Subchondral erosions(“pseudo-widening” of the SI joint)
Subchondral sclerosis
SI joint narrowing
Fusion of the SI joint (end-stage)

Spinefindings:
Small erosions with reactivesclerosis
Squaring of vertebrae
Ligament calcifications
Evolving syndesmophytes
Bridging syndesmophytes (“bamboospine”)

MRI:
Aidsin early detection
May reveal inflammatory changes not seen on radiographs

Question 17

AS

Lab tests

Answer 17

Lab tests:
↑ CRP and erythrocyte sedimentation rate(ESR)
Mildly ↑alkaline phosphatase
Negativerheumatoid factor (RF)
Negative ANA test

Genetic testingfor HLA-B27:
May be considered if clinical evaluation and radiography are inconclusive
Positive in approximately 90% of patients with AS
Not required for diagnosis

Question 18

AS

Lifestyle Tx

Answer 18

Lifestyle changes:
Smoking cessation
Regular physical activity

Physical therapy:
Crucial for maintainingmobility
Exercises for:
Mobilization of the vertebral joints and muscle stability
Maintenance of adequate posture andrange of motion

Question 19

AS

Med Tx

Answer 19

Initial therapy:
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Scheduled dosing not as-needed dosing
70% ofpatientsachieve clinical improvement
2 differentNSAIDsshould be tried before escalating to 2nd-line therapy

Glucocorticoids
Intraarticular glucocorticoid injections are considered in peripheralspondyloarthropathy(particularly in disease localized to ≤ 2 joints)
Long-term systemic glucocorticoid use isNOTrecommended
Short-termsystemic glucocorticoidscan be considered for symptom relief

2nd line:
Disease-modifying antirheumatic drugs (DMARDs)
Sulfasalazineormethotrexate
Used for persistentperipheral arthritis

TNFinhibitors
Used inpatientswho fail NSAIDtherapy

Question 20

AS

Surgery

Answer 20

Surgical interventions
Severe deformities resulting in functional impairment
Severepaincausing diminishedqualityof life
Acutefracture
Neurologic deficits

Options:
Spinal fusion
Osteotomy
Total hiparthroplasty

Question 21