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In-Depth Information
3.2.3 Treatment
Treatment of psoriatic arthritis is varied because of the diversity of clinical pre-
sentations. For mild arthritis, NSAIDs are the
first line treatment to control
symptoms. For patients with peripheral arthritis affecting more than 3 joints, a
disease modifying anti-rheumatic drug (DMARD) is often considered, such as
le
fl
unomide, sulfasalazine, cyclosporine, or methotrexate [
58
,
59
]. Methotrexate is
the
first choice of many rheumatologists.
Anti-TNF agents have shown effectiveness in controlling acute in
ammation
and preventing bony erosions in psoriatic arthritis. Alefacept, a fusion protein
targeting lymphocyte function antigen 3 (LFA3), and ustekinumab, an interleukin
12/23 inhibitor, are also effective.
Conventional DMARDs and newer biologics may have some effect on other
manifestations, such as enthesitis and spondylitis. However, responses of these
manifestations have not been well studied.
fl
3.2.4 Imaging
Plain radiography remains the standard for diagnosing psoriatic arthritis and
monitoring its progression. A characteristic finding of psoriatic arthritis is the
co-existence of erosions and new bone formation, most prominent at the
nger
joints. Absorption and lysis of the
finger bones may lead to typical
'
pencil-in-cup
'
appearance on radiographs. Fusion of hand bones,
fl
uf
ness of the bony cortex, and
calci
cation of entheses are evidence of new bone formation. The sacroiliac joints
are occasionally involved in psoriatic arthritis, and erosion, sclerosis and ankylosis
of these joints are common
findings. Dynamic imaging of the cervical spine, with
fl
flexion and extension of the head, may reveal instability of the cervical spine.
Spinal radiographs may depict syndesmophytes, which tend to originate from the
mid-part of
the vertebral body rather
than the vertebral corner, and spine
involvement is often discontinuous.
Radiographic progression of psoriatic arthritis is slow. Radiographic scoring
systems have been adapted from rheumatoid arthritis but modi
ed to include the
distal interphalangeal joints, and are used to assess joint erosions and disease
progression in clinical trials.
MRI has been used to assess enthesitis in psoriatic arthritis, and led to new
understanding of its pathogenesis. In
ammation of the entheses and associated
bone marrow edema are the most common MRI
fl
finding. It has been proposed to use
MRI of the spine and sacroiliac joints as a more sensitive way to assess spinal
involvement in psoriatic arthritis; however, at present, it is still limited to research
settings.
