Page 803 - Robbins Basic Pathology by Vinay Kumar, Abul K. Abbas, Jon C. Aster
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(great toe), and 90% in the instep, ankle, heel, or wrist. Arthritis 789
Untreated, acute gouty arthritis may last for hours to
weeks, but it gradually completely resolves, and the patient spread from osteomyelitis or a soft tissue abscess. Infec-
enters an asymptomatic intercritical period. Although some tious arthritis is serious because it can cause rapid joint
fortunate persons never have another attack, most experi- destruction and permanent deformities.
ence a second episode within months to a few years. In the
absence of appropriate therapy, the attacks recur at shorter Suppurative Arthritis
intervals and frequently become polyarticular. Eventually,
after a decade or so, symptoms fail to resolve completely Bacteria can seed joints during episodes of bacteremia; joint
after each attack, and the disease progresses to chronic infection with such microorganisms almost uniformly
tophaceous gout. At this stage, radiographs show character- results in a suppurative arthritis. Although virtually any
istic juxtaarticular bone erosion caused by the crystal bacteria can be causal, Haemophilus influenzae predominates
deposits and loss of the joint space. Progression leads to in children younger than 2 years of age, S. aureus is the
severe crippling disease. main causative agent in older children and adults, and the
gonococcus is prevalent in older adolescents and young
Renal manifestations of gout can appear as renal colic adults. Patients with sickle cell disease are prone to Salmo-
associated with the passage of gravel and stones, and can nella infection at any age. Both genders are affected equally,
evolve into chronic gouty nephropathy. About 20% of except for gonococcal arthritis, which occurs mainly in
persons with chronic gout die of renal failure. sexually active women. In this group, those with deficiency
of certain complement proteins (C5, C6, and C7) are par-
Numerous drugs are available to abort or prevent acute ticularly susceptible to disseminated gonococcal infections
attacks of arthritis and mobilize tophaceous deposits. Their and hence arthritis.
use is important, because many aspects of gout are related
to the duration and severity of hyperuricemia. Generally, The classic presentation is one of sudden onset of pain,
gout does not materially shorten the life span, but it can redness, and swelling of the affected joint(s), with restricted
certainly impair quality of life. range of motion. Fever, leukocytosis, and elevated erythro-
cyte sedimentation rate are common. In gonococcal infec-
Pseudogout tions, the course tends to be more subacute. In 90% of cases
of nongonococcal suppurative arthritis, the infection
Pseudogout also is known as chondrocalcinosis or, more for- involves only a single joint—usually the knee—followed in
mally, calcium pyrophosphate crystal deposition disease. order by hip, shoulder, elbow, wrist, and sternoclavicular
The crystal deposits first appear in structures composed of joints. Joint aspiration typically yields a purulent fluid in
cartilage such as menisci, intervertebral discs, and articular which the causal agent can be identified.
surfaces. When the deposits enlarge enough, they may
rupture, inducing an inflammatory reaction. Pseudogout Lyme Arthritis
typically first occurs in persons 50 years of age or older,
becoming more common with increasing age, and eventu- Lyme disease is caused by infection with the spirochete
ally reaching a prevalence of 30% to 60% in those age 85 or Borrelia burgdorferi, transmitted by deer ticks of the Ixodes
older. There is no gender or race predilection. ricinus complex; it is named for the Connecticut town
where the disease was first recognized in the 1970s. With
Although pathways leading to crystal formation are not more than 20,000 cases reported annually, it is the leading
understood, they are likely to involve the overproduction arthropod-borne disease in the United States. As with
or decreased breakdown of pyrophosphate, resulting in its another major spirochetal disease, syphilis, Lyme disease
accumulation and eventual crystallization with calcium in involves multiple organ systems and in its classic form
the matrix surrounding chondrocytes. Mutations in a progresses through three successive stages. In stage 1,
transmembrane pyrophosphate transporter are associated Borrelia spirochetes multiply at the site of the tick bite
with a rare familial form of the disease, in which crystals and cause an expanding area of redness, often with an
develop relatively early in life and there is severe indurated or pale center. This skin lesion, called erythema
osteoarthritis. chronicum migrans, may be accompanied by fever and
lymphadenopathy but usually disappears in a few weeks’
Much of the subsequent joint pathology in pseudogout time. In stage 2, the early disseminated stage, spirochetes
involves the recruitment and activation of inflammatory spread hematogenously and cause secondary annular skin
cells and is similar to that in gout (see earlier). Duration of lesions, lymphadenopathy, migratory joint and muscle
clinical signs can be from several days to weeks, and joint pain, cardiac arrhythmias, and meningitis, often with
involvement may be monoarticular or polyarticular; the cranial nerve involvement. Diagnostically useful antibod-
knees, followed by the wrists, elbows, shoulders, and ies (usually both IgM and IgG) against Borrelia antigens
ankles, are most commonly affected. Ultimately, approxi- appear in the serum at this stage of the disease. Some
mately 50% of patients experience significant joint damage. spirochetes, however, escape host antibody and T cell
Therapy is supportive; no known treatment prevents or responses by sequestering themselves in the central nervous
retards crystal formation. system or within endothelial cells. In stage 3, the late dis-
seminated stage, which occurs 2 or 3 years after the initial
Infectious Arthritis bite, Lyme Borrelia organisms cause a chronic arthritis,
sometimes with severe damage to large joints, and an
Microorganisms of any type can lodge in joints during encephalitis that ranges in severity from mild to
hematogenous dissemination. Articular structures can also debilitating.
become infected by direct inoculation or by contiguous
Lyme arthritis develops in roughly 60% to 80% of
untreated patients and is the dominant feature of late
