C h a p t e r 4 4
Disorders of the Skeletal System: Metabolic and Rheumatic Disorders
1135
of 7 years.
80,81
There is an increased incidence among
girls. The cause is unknown, but there is a history of
infection in the 3 months before disease onset in most
affected children. Symmetric proximal muscle weak-
ness, elevated muscle enzymes, evidence of vasculitis,
and electromyographic changes confirming an inflam-
matory myopathy are diagnostic for JDM. The rash
may precede or follow the onset of proximal muscle
weakness. Periorbital edema with swelling and purple
red discoloration of the upper eyelid is common. An
erythematous (red) papulosquamous (containing both
papules and scales) rash may also be present on the dor-
sal surfaces of the finger joints and on the extensor sur-
faces of the elbows and knees. Ulcerative skin disease is
a serious and potentially life-threatening manifestation
of JDM.
Calcifications can occur in 30%to 50%of childrenwith
JDM and are by far the most debilitating symptom. The
calcifications appear at pressure points or sites of previ-
ous trauma. Juvenile dermatomyositis is treated primarily
with corticosteroids to reduce inflammation. DMARDs,
such as methotrexate, may be used as a steroid-sparing
agent in cases of refractory disease. All children with JDM
should avoid exposure to the sun, use a sunscreen with a
sun protection factor (SPF) greater than 36, eat a calcium-
sufficient diet, and take vitamin D therapy.
81
Rheumatic Diseases in the Elderly
Rheumatic disorders are common causes for complaint
among elderly persons.
82,83
Pain and severe limitations in
function often threaten independence and quality of life.
The weakness and gait disturbance that often accom-
pany the rheumatic diseases can increase the risk of falls
and fracture, causing suffering, increased health care
costs, and further loss of independence.
Arthritic complaints in the elderly are most frequently
associated with degenerative forms of arthritis, such as
osteoarthritis, but forms of inflammatory arthritis such
as rheumatoid and gouty arthritis are also seen. One
form of rheumatic disease that has a predilection for the
elderly is polymyalgia rheumatica.
Osteoarthritis
Osteoarthritis is by far the most common form of arthri-
tis among the elderly.
82
It may affect any joint but is
most common in the spine and small joints of the hand,
particularly the distal interphalangeal joints, and knees,
hip, ankle, and shoulder. When the upper extremity
joints are affected, activities of daily living, such has
holding on to an object, putting on a coat, buttoning
a shirt, or turning a key may be a problem. When the
lower extremities are involved, climbing and descending
stairs and getting out of a chair are difficult.
Management of OA in older persons includes
both conservative management and surgical correc-
tion or joint replacement.
82
Conservative management
focuses on rehabilitative and pharmacologic measures.
Rehabilitative measures are directed at reducing the
load on the affected joint and maintaining joint mobility.
Weight reduction significantly reduces the load in per-
sons in whom weight-bearing joints are involved.
Although resting painful arthritis joints is helpful in the
short term, prolonged inactivity will lead to the more
serious problem of immobility. Exercise programs are
important to maintain joint motion and strength. Both
passive and active exercises should be encouraged. The
use of a cane will significantly reduce the loading force
in all lower extremities and should be recommended to
allow for continuation of a walking program. Attention
to environmental hazards to prevent falls is essential.
For persons with knee involvement, bracing and orthot-
ics provide a shift in the medial knee compartment and,
in so doing, may provide considerable relief of pain
and improvement in function. The use of appropriate
footwear may also reduce joint forces for persons with
arthritic involvement of the lower extremities.
Pharmacologic treatment is accomplished mainly
through the use of NSAIDS and analgesics.
82
As the
disease progresses, these medications become less effec-
tive and other methods such intra-articular hydrocorti-
sone injection may be used. Injection of hyaluronic acid
preparations into the knee may be used as an alternative
to steroids. Surgical treatment, including joint replace-
ment, may be indicated for severely arthritic joints that
are unresponsive to conservative treatment.
Rheumatoid Arthritis
The prevalence of RA increases with advancing age.
83,84
There are two distinct clinical presentations of RA in
older persons: RA diagnosed before age 60, and elderly
onset RA (EORA), in which the disease is first diag-
nosed after age 60. There is a slightly less female pre-
dominance and acute onset with marked elevations in
inflammatory markers than in persons diagnosed at
an earlier age. There is also significant morning stiff-
ness, with prominent involvement of the upper extremi-
ties, particularly the shoulders. This is in contrast to
older persons who have had disease activity for several
decades and demonstrate advanced sequelae of the dis-
ease and its treatment.
Whether either form of RA has a better prognosis
than the other is uncertain. Both forms require special
considerations in terms of pharmacologic therapy, and
both can have a negative impact on the functional status
of the elderly.
Crystal-Induced Arthropathies
The two best-recognized forms of crystal-induced joint
disease are caused by the deposition of monosodium
urate (gout) and calcium pyrophosphate (pseudogout).
85
Gout typically has its onset in middle-aged adults,
whereas pseudogout has an increasing prevalence in
older adults and is often associated with unique and
atypical features.
Gout.
The incidence of clinical gout increases with
advancing age, in part because of the increased involve-
ment of joints after years of continued hyperuricemia.
