Page 367 - Medicine and Surgery

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Chapter 8: Seronegative arthritides (spondyloarthropathies) 363

Complications Age
Spinal fractures may occur with minimal trauma due to Peak incidence age: 30–50 years.
localised osteoporosis (secondary to immobility and in-
flammation).Atlantoaxialsubluxationandcaudaequina Sex
syndrome may occur. 1:1
Aetiology
Investigations
Genetic factors: Psoriasis and psoriatic arthritis have
Inflammatory markers (particularly CRP) are often

a familial tendency particularly in first-degree rela-
elevated in active phases of the disease, although may
tives.Therearesometwinstudiessuggestingincreased
be normal even with severe disease.
monozygotic concordance. A number of HLA anti-
X-rays may be normal in early stages.

gens are related to the development of psoriasis and
1 Early signs on bilateral AP views of sacroiliac joints
psoriatic arthritis especially B27, and there are genetic
are of sclerosis and erosions in the sacroiliac joints,
linkage studies to a number of loci.
2 Lateralviewsoflumbarspineshowerosionsofedges
Environmental factors include bacterial and viral
of vertebral bodies, squaring of the vertebrae, syn-
infections and trauma. Trauma may be implicated
desmophyte formation and ‘bamboo’ spine.
as psoriatic skin lesions exhibit the Koebner phe-
nomenon (lesion develop at sites of trauma).
Management
Major objectives are to relieve the pain and stiffness. Pathophysiology
Patients should be encouraged to remain active, avoid Synovitis is histologically the same as that of rheumatoid

prolonged bed rest and avoid lumbar supports. Phys- arthritis, although bone resorption is sometimes promi-
iotherapy involvement is important. nent.Itislikelythatboththeskinlesionsandthearthritis
Pain and morning stiffness are treated with non- are immunologically mediated.

steroidal anti-inflammatory drugs.
Large joint involvement may also respond to drugs Clinical features

such as sulphasalazine. Anti-TNF-α antibodies have There are usually psoriatic lesions of the skin but the
been shown to be effective in severe disease. severity is unrelated to the development of arthritis (see
Surgery may be indicated for disease in large joints page 387). Psoriatic nail involvement is related to an in-

(including arthroplasty). A lumbar or cervical spinal creasedriskofpsoriaticarthritis.Fivepatternsofarthritis
osteotomy may be helpful in patients with severe cur- are seen:
vature. 1 Distal interphalangeal joint synovitis, which is often
asymmetrical.
Prognosis 2 Asymmetric oligo/monoarthritis.
There is a wide range of severity: In over 85% there is 3 Symmetrical rheumatoid-like polyarthritis.
minimal disability, 50% of patient’s children will inherit 4 Arthritis mutilans is a rare deforming – destructive
HLA B27 and of these, 33% will develop the condition. arthritis with marked bone resorption.
5 Spondyloarthropathy similar to ankylosing spondyli-
tis affects the spine and sacroiliac joints.
Psoriatic arthritis
Investigations
Definition Blood tests may show raised inflammatory markers,
Achronic inflammatory arthritis occurring with psori- anaemia of chronic disease and presence of autoanti-
asis. bodies (ANA and RhF).
X-ray: There is a combination of erosions and new

Prevalence bone formation in distal joints. Other features include
1% of population have psoriasis of which 5% will get periostitis, bone resorption, sacroiliitis and spondyli-
arthritis. tis.