Psoriatic arthritis is an inflammatory arthritis associated with psoriasis,
a chronic skin and nail disease. There are five types of this disease:
- Arthritis involving primarily the small joints of fingers or toes
- Asymmetrical arthritis, which involves joints of the extremities
- Symmetrical polyarthritis, which resembles rheumatoid arthritis
- Arthritis mutilans, which is rare but very deforming and destructive
- Arthritis of the sacroiliac joints and spine (psoriatic spondylitis)
The exact prevalence of each of these forms of arthritis is difficult
to establish. Patterns may themselves change with time in individual patients, and some patients may show overlapping features
or more than one type. Sometimes arthritis is associated with inflammation of the eyes, or inflammation at the bony sites
of attachment of ligaments and tendons, causing local pain, for example at the heels.
CAUSE
The exact cause is unknown, but an interplay of immune, genetic, and
environmental factors are suspected. Up to 40% of patients with psoriatic arthritis may have a history of psoriasis or arthritis
in family members.
HEALTH IMPACT
- Psoriatic arthritis affects at least 10% of the 3 million people with
psoriasis in the United States.
- It affects men and women equally and usually begins between 30-50 years
of age, but can begin in childhood.
- Psoriatic arthritis may precede the onset or the diagnosis of psoriasis
in up to 15% of patients.
DIAGNOSIS
Skin and nail changes characteristic of psoriasis must be demonstrated
before a diagnosis can be made with certainty. Elevated erythrocyte sedimentation rate (ESR), mild anemia, and elevated levels
of blood uric acid can be seen in some patients. Gout must be excluded.
TREATMENT
Initial treatment of psoriatic arthritis consists of the use of nonsteroidal
anti-inflammatory drugs (NSAIDs), but methotrexate may be needed for arthritis that doesnt respond. An antimalarial drug,
hydroxychloroquine, may be effective, but some patients experience a flare of their psoriasis. Sulfasalazine has been found
to be very beneficial for some psoriatic arthritis patients. Azathioprine may be used in severe cases of the disease.
Corticosteroid injections directly into the joints can be useful. Cyclosporin
has been used recently with some good results, but because of kidney side effects, it should be reserved for patients with
progressive disease unresponsive to other measures. Proper exercise is very important. Surgery can be helpful in patients
who develop joint destruction.
Scleroderma is a chronic autoimmune disease that was first described
in the 18th century. The term scleroderma means "hard skin," which describes thickening of the skin from increased deposits
of collagen.
There are two types of scleroderma. Localized scleroderma affects the
skin in limited areas and the musculoskeletal system. Systemic sclerosis causes more widespread skin changes and may be associated
with internal organ damage in the lungs, heart and kidneys. It can cause arthritis, slow contractions in the gastrointestinal
tract, muscle inflammation, dry eyes and dry mouth. Most people with scleroderma have cold-induced spasms of small blood vessels
in their hands or feet, known as Raynauds phenomenon, which caused the fingers or toes to turn white or blue and may be painful.
CAUSE
In most cases, the cause of scleroderma is unknown. However, in a small
minority of cases, scleroderma or scleroderma-like illnesses are associated with exposure to certain toxins or as a complication
of bone marrow transplants. Scleroderma is not contagious and is rarely inherited.
Systemic sclerosis is associated with over-activation of the immune system,
which normally functions to protect the body against cancers and invading infections. This causes damage to cells that line
small blood vessels, which in turn leads to the over-production of scar tissue.
HEALTH IMPACT
- Scleroderma affects women more than men and adults more than children.
- 10-20 new cases are diagnosed per million people each year.
- Five-year survival rate is 80 85 percent.
- Lung, heart and kidney damage are the most frequent causes of severe
disability and death.
- Many people have decreased hand function because of joint disfigurement
or finger ulcers.
DIAGNOSIS
Diagnosis of scleroderma is based on clinical history and physical findings.
Diagnosis may be delayed in those without significant skin thickening. Laboratory, X-ray and pulmonary function tests determine
the extent and severity of internal organ involvement.
TREATMENT
There is no known cure for scleroderma. No treatment has been scientifically
proven to alter the overall course of the disease, although d-penicillamine is commonly used for this purpose and may be of
some value.
There are a number of effective organ-specific treatments for scleroderma.
Raynauds phenomenon may be helped by calcium channel blockers. Declining renal function and hypertension are often treated
with drugs. Esophageal damage from reflux of stomach contents can be treated with acid-reducing drugs. Antibiotics, special
diets and medication can improve absorption of nutrients in people who have abnormalities of their intestines. Musculoskeletal
pain may respond to nonsteroidal anti-inflammatory agents. Lung inflammation may be treated with cyclophosphamide.
Physical and occupational therapies are used to minimize joint disability
and functional impairment.
Glossary of clinical terms used in description or classification of systemic sclerosis
1. Typical sclerodermatous skin changes: tightness, thickening, and non-pitting
induration, excluding the localized forms of scleroderma (morphea or linear scleroderma)
a) Sclerodactyly: above-indicated changes limited to (fingers and toes).
b) Proximal scleroderma: above-indicated changes proximal to the metacarpophalangeal
or metatarsophalangeal joints, affecting other parts of the extremities, face, neck, or trunk (thorax or abdomen); usually
bilateral, symmetrical and almost always including sclerodactyly
2. Other skin manifestations attributable to systemic sclerosis
or comparison disorders
a) Digital pitting scars or loss of substance from the finger pad: depressed
areas at tips of digits or loss of digital pad tissue as a result of digital ischemia rather than trauma or exogenous causes
b) Bilateral finger or hand edema: firm but pitting edema, especially
involving fingers (includes puffy sausage-like swelling of fingers) or the dorsal aspect of the hands
c) Abnormal skin pigmentation: hyperpigmentation often containing areas
of punctate or patchy hypopigmentation or depigmentation ("pepper and salt")
d) Raynaud's phenomenon: at least two-phase color change in fingers and
often toes consisting of pallor, cyanosis, and/or reactive hyperemia in response to cold exposure or emotion, as determined
by patient's history or physician's observation
3. Visceral manifestationsa) Bibasilar pulmonary fibrosis: bilateral
reticular pattern of linear or lineonodular densities which are most pronounced in basilar portions of the lungs on standard
chest roentgenogram; may assume appearance of diffuse mottling or "honeycomb lung," and should not be attributable to primary
lung disease
b) Lower (distal) esophageal dysphagia: substernal discomfort on swallowing
or sensation of food holdup in the retrosternal location
c) Lower (distal) esophageal dysmotility: hypoperistalsis or aperistalsis,
as demonstrated by either cine esophagram or fluoroscopy or by manometric study, often accompanied by evidence of decrease
in lower esophageal sphincter tone with reflux of gastric contents into the esophagus
d) Colonic sacculations: wide-mouthed diverticula of colon located along
the antimesenteric border; found on barium enema examination; these sacculations may also occur in ileum and jejunum
Ankylosing spondylitis (AS) is a rheumatic disease that causes arthritis
of the spine and sacroiliac joints and can cause inflammation of the eyes, lungs, and heart valves. It varies from intermittent
episodes of back pain that occur throughout life to a severe chronic disease that attacks the spine, peripheral joints and
other body organs, resulting in severe joint and back stiffness, loss of motion and deformity as life progresses.
AS is a member of the family of diseases that attack the spine called
spondylarthropathies. In addition to AS, these diseases include Reiters syndrome, some cases of psoriatic arthritis and the
arthitis of inflammatory bowel disease.
CAUSE
The cause of AS is not known, but all of the spondylarthropathies share
a common genetic marker, called HLA-B27, in most affected individuals. In some cases, the disease occurs in these predisposed
people after exposure to bowel or urinary tract infections.
HEALTH IMPACT
- AS afflicts an estimated 129 out of 100,000 people in the United States.
- AS typically strikes adolescents and young adult males.
- The prevalence of AS varies by ethnic group and is most common in Native
Americans.
DIAGNOSIS
Delayed diagnosis is common because symptoms are often attributed to
more common back problems. A dramatic loss of flexibility in the lumbar spine is an early sign of AS. Although most symptoms
begin in the lumbar and sacroiliac areas, they may involve the neck and upper back as well. Arthritis may also occur in the
shoulder, hips and feet. Some patients have eye inflammation, and more severe cases must be observed for heart valve involvement.
At times, AS may presage the development of inflammatory bowel disease,
and some patients have fever, fatigue, weight loss, anemia, eye inflammation (called iritis), and more severe cases may involve
heart valve dysfunction. Other disorders of the internal organs and bones mimic spondylarthropathies and must be distinguished.
Laboratory evaluation may reveal an elevated sedimentation rate (an indicator of inflammation), anemia and a positive HLA-B27
assay. X-rays and bone scans may show characteristic changes.
TREATMENT
The severity of joint involvement and the degree of systemic symptoms
vary greatly from one individual to another. Early, accurate diagnosis and therapy may minimize years of pain and disability.
Medical treatment consists of nonsteroidal anti-inflammatory medications.
Indomethacin is most effective, while sulfasalazine may benefit those with more severe involvement. Peripheral joint arthritis
may respond to methotrexate.
Rehabilitation therapies are essential. Proper sleep and walking positions,
coupled with abdominal and back exercises, help maintain posture. Exercises help maintain joint flexibility. Breathing exercises
enhance lung capacity, and swimming provides aerobic exercise. Even with optimal treatment, some people will develop a stiff
or "ankylosed" spine, but they will remain functional if this fusion occurs in an upright position. Continuing care is critical.
AS is a lifelong problem, and people often fail to continue treatment, in which case permanent posture and mobility losses
occur.
In the early 20th century, Swedish physician Henrik Sjögren
(SHOW-gren) first described a group of women whose chronic arthritis was accompanied by dry eyes and dry mouth. Patients complain
of irritation, a gritty feeling or painful burning in the eyes. Eyelids may stick together and patients may complain of mouth
dryness. Food is difficult to chew and swallow. About half of Sjögrens syndrome patients also have rheumatoid arthritis or
other connective tissue disease.
CAUSE
Sjögrens syndrome is a disorder of the immune system, which normally
functions to protect the body against cancers and invading infections. The several factors involved include genetic, immunologic,
hormonal, and probably infectious. People with this disease have abnormal proteins in their blood that suggest that their
immune system is reacting against their own tissue. The decreased production of tears and saliva is caused when the glands
that produce these fluids are damaged. These glands are attacked by immune cells called lymphocytes. In a small number of
people, Sjögrens syndrome is associated with lymphoma, a form of cancer.
HEALTH IMPACT
- Between 1 and 4 million Americans have Sjogrens syndrome.
- It occurs 10 times more often in women than in men.
- Onset can occur at any age, but usually between 45 and 55.
DIAGNOSIS
Sjogrens syndrome is diagnosed by blood tests, a decrease in tear and
saliva production, X-rays of salivary glands, and lip biopsy.
TREATMENT
Treatment depends on symptoms. No treatment, however, has yet been found
to restore glandular secretions. Ocular dryness responds to the use of artificial tears applied every one to three hours.
Dry mouth can be relieved by drinking water, chewing gum, or using saliva stimulants (such as pilocarpine). For life threatening
complications, medications such as corticosteroids and cyclophosphamide are occasionally needed.
Crohn's Disease:
The long delays between the onset of Crohn's disease and presentation are in sharp contrast to ulcerative colitis, which
tends to be diagnosed promptly because patients almost always have bloody stools. The manifestations of Crohn's disease can
be much more subtle, depending on disease location and severity. For example, a woman in her 30s--felt perfectly healthy until
she tried to take a vitamin tablet directly from the bottle and accidentally swallowed the plastic desiccant. The desiccant
lodged in her intestine in a stricture caused by longstanding Crohn's disease.
Another impediment to recognition of Crohn's disease is its widely varied presentation. Crohn's disease can affect any
portion of the digestive tract with any degree of severity. When the stomach is affected, the disease can present like an
ulcer or gastritis does; if it is in the small intestine, it may present as cramps, nausea, diarrhea, or weight loss; if in
the colon, as abdominal pain, change in bowel habits, or bleeding. More than one site may be affected. Involvement of the
ileum and colon is most common, occurring in up to 50% of cases. Perianal lesions occur in 25% to 30% of cases and may occasionally
dominate the clinical picture.
Moreover, Crohn's disease is not especially common. In the United States, its incidence is five cases per 100,000 persons
per year, and its prevalence is 50 per 100,000. In contrast, a third of the population has the symptoms of irritable bowel
syndrome at some point in their lives. Consequently, mild or nonspecific abdominal complaints caused by Crohn's disease in
a young patient may be erroneously attributed to irritable bowel. The correct diagnosis may not be made until the appearance
of moderate to severe manifestations such as fever, weight loss, abdominal pain and tenderness, nausea and vomiting, anemia,
or extraintestinal manifestations such as arthritis or erythema nodosum (the "bruise" on this patient's shin). Affected teenagers
often are shorter than normal, presumably because of prolonged subclinical disease.
To further complicate matters, a patient may have both irritable bowel syndrome and Crohn's disease. Assuming that the
incidence of irritable bowel syndrome is the same among patients with Crohn's disease as in the general population, there
will be an irritable bowel component in a third of patients with Crohn's disease. The physician needs to address inflammatory
and noninflammatory symptoms separately in such cases.
A Clinicopathologic Diagnosis
There is no gold standard of diagnosis of Crohn's disease--no definitive blood test result or pathognomonic biopsy finding.
Diagnosis instead depends on whether the patient fits the clinicopathologic scenario for the disease. I believe this lack
of diagnostic specificity reflects an underlying etiologic heterogeneity; indeed, I expect that in the years to come the development
of new serologic tests will demonstrate that Crohn's disease is not a single entity but a series of disorders.
Two new tests are beginning to be used to differentiate Crohn's disease from ulcerative colitis: the perinuclear antineutrophil
cytoplasmic antibody (pANCA) and anti-Saccharomyces cerevisiae antibody (ASCA) assays. Neither is ideal. The pANCA
assay has reasonable sensitivity but low specificity for ulcerative colitis, while the ASCA assay has high specificity but
very low sensitivity for Crohn's disease.
Clinical suspicion of Crohn's disease is based on a finding of white blood cells in the feces. Most patients present with
diarrhea, and since the first consideration on the differential diagnosis would be infectious diarrhea, the physician usually
orders cultures for parasites and ova and Clostridium difficile. If they are negative, stool samples are stained with
methylene blue--if neutrophils are present, the patient has inflammatory diarrhea. In the absence of cultures, the digestive
tract can be assessed by colonoscopy or barium enema and barium contrast studies of the small intestine. The pathologic hallmarks
of Crohn's disease are focal and transmural inflammation, with or without granuloma formation.
If the patient presents with symptoms resembling peptic ulcer, upper gastrointestinal endoscopy will help to distinguish
Crohn's disease from gastritis caused by Helicobacter pylori. Only about 5% of cases of Crohn's disease present with
gastric involvement, however.
Pathogenic and Epidemiologic Considerations
Like other autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, and psoriasis, Crohn's disease appears
to involve a genetic predisposition and an overly active immuno-inflammatory response. One hypothesis is that the immune system
mounts a response against a bacterial antigen that spills over to include body components that resemble the antigen (molecular
mimicry). Such an event could occur because of homologous human and bacterial genetic material. The specific clinical manifestation
of disease caused by molecular mimicry would depend on which body component the foreign antigen resembles: if a constituent
of thyroid cell, the result may be thyroiditis; if a nerve sheath, multiple sclerosis; if an intestinal cell, Crohn's disease.
Most of these diseases are probably enteric in origin, because the intestinal immune system is the body's immunologic eye
to the world. Many antigens are processed through the intestine, which must discriminate among the innumerable bacteria and
components of digestion what is necessary for metabolism and needs to be absorbed and what needs to be passed through because
it is potentially harmful.
The gut is normally in a state of controlled chronic inflammation. Among persons in the tropics, the degree of inflammation
is especially high. The extreme there is tropical sprue, in which inflammation is so severe that the intestine's absorptive
capability is almost eliminated. Intestinal inflammation tends to be less prominent in persons in developed countries who
live in relatively sanitary environments. The counterpart of a person with tropical sprue would be someone raised in a germ-free
environment and lacking intestinal inflammatory cells.
Interestingly, the prevalence of autoimmune inflammatory diseases correlates directly with the cleanliness of the environment.
Such diseases are most common in northern and western Europe and North America and are rare in the tropics. There are also
some ethnic variations. Autoimmune inflammatory diseases are more common among Jews than non-Jews, and among Caucasians than
other races. We are beginning to see shifts in disease patterns, however, particularly as different ethnic groups migrate
into Western society. For example, autoimmune diseases are more common among Japanese, Hispanics, and Africans living in the
United States and Europe than those living in their native countries.
One other interesting environmental factor is cigarette smoking. For unknown reasons, cigarette smoking is the only epidemiologic
factor that is different for ulcerative colitis and Crohn's disease--it "prevents" ulcerative colitis but has a strong association
with Crohn's disease. This pattern also occurs with other autoimmune diseases--for example, smoking protects against Hashimoto's
disease but is associated with Graves' disease.
Flares of Crohn's disease may result from cigarette smoking, as well as from respiratory or enteric infection and use of
nonsteroidal anti-inflammatory drugs. There is no definitive evidence that psychological factors, such as work-related stress,
cause flares.
