Internal-Medicine

196 9: Muscles and Joints
50. (D) This story is typical of Lyme disease. The
spirochete involved (B. burgdorferi) is transmitted
by ixodic ticks and is most common in the
Northeastern and Midwestern parts of the
United States. The host animal varies depending
on the exact type of tick. Because antibody
studies cannot differentiate between active and
inactive disease, the appropriate constellation
of symptoms is also required for diagnosis.
(Kasper, p. 997)
51. (E) As in most inflammatory arthritides, the
patient with RA generally has morning stiffness
for more than 1 hour. Wrist involvement is
nearly universal and is associated with radial
deviation (unlike the ulnar deviation of the
digits) and carpal tunnel syndrome. Hand
involvement characteristically involves the
proximal interphalangeal and MCP joints in a
symmetric involvement. High fever (>100.4°F),
even with active synovitis, should suggest an
intercurrent problem such as infection. (Kasper,
pp. 1970–1971)
52. (C) AS occurs in 1–6% of adults inheriting
human lymphocyte antigen B27 (HLA-B27).
However, the prevalence in B27-positive relatives
of patients with AS is up to 30%. Men are
three times more likely to be affected. (Kasper,
p. 1993)
53. (D) This patient has PMR. It is characterized by
stiffness, aching, and pain in proximal muscle
groups in the neck, shoulders, back, hips, and
thighs. It is considerably more common than
temporal arteritis. Both diseases are almost
exclusively seen in the over 50 age group.
(Kasper, p. 2009)
54. (A) Although all these complications have been
reported in giant cell arteritis, the only one with
a significant likelihood is blindness secondary
to ischemic optic neuropathy. Thus, if the disease
is suspected, urgent diagnosis and treatment
is required. (Kasper, p. 2009)
55. (C) Although the hallmark of osteoarthritis is
the progressive loss of articular cartilage, it is
best considered as a disease of the entire organ,
the synovial joint, rather than of any of its
component tissues. In fact, all areas of the joint,
bone, cartilage, synovium, meniscus, and ligaments
are involved. (Kasper, p. 2038)
56. (B) In Marfan syndrome, inheritance is autosomal
dominant, and the aortic lesion is a cystic
medial necrosis with loss of elastic tissue,
resulting in aneurysm formation. Pneumothorax
can occur but is not as characteristic. Mitral
valve prolapse can also be part of the syndrome.
Dislocation of the lens is the most
apparent eye abnormality. Severe chest deformities
and long limbs are characteristic. High,
arched palate; high pedal arches; and pes
planus are common. (Kasper, p. 2330)
57. (A) Numerous mediators of inflammation are
found in the synovium of patients with
rheumatoid arthritis (RA). The evidence favoring
activated T cells as the initiators of the
inflammation include the predominance of
CD4 + T cells in the synovium, the increase in
soluble interleukin-2 (IL-2) receptors (a product
of T-cell activation), and amelioration of symptoms
by T-cell removal. (Kasper, p. 1969)
58. (C) Methotrexate, 7.5–20 mg once weekly, is
the most commonly recommended disease
modifying drug, because its effect is more rapid
and patients are able to tolerate it for longer
periods of time. Maximum improvement with
methotrexate occurs after 6 months of therapy.
Toxicity includes GI upset, oral ulceration, and
liver function abnormalities. GI upset in particular
may be ameliorated by concurrent folic
acid administration. Pneumonitis has also been
reported. (Kasper, p. 1975)
59. (B) ANAs are present in 98% of patients with
SLE. Repeatedly negative tests make the diagnosis
of SLE very unlikely. Unfortunately, the
test is not specific and may be positive in
normal people (especially in older individuals),
or secondary to infections, drugs, or other
autoimmune disorders. (Kasper, p. 1964)
60. (E) This patient likely has PAN. ANCA and
other serology are usually negative in PAN;
positive serology suggests another diagnosis.
The optimal diagnostic strategy is the biopsy of