A 45-year-old woman with long-standing, well-controlled rheumatoid arthritis develops severe pain and swelling in the left elbow over 2 days. She is not sexually active. Arthrocentesis reveals cloudy fluid. Synovial fluid analysis reveals greater than 100,000 cells/mL; 98% of these are PMNs. What is the most likely organism to cause this scenario?
Staphylococcus aureus is the most common organism to cause septic arthritis in adults. β-Hemolytic streptococci are the second most common. N gonorrhoeae can also produce septic arthritis, but would be less likely in this patient who is not sexually active. S pneumoniae and gramnegative rods such as E coli or P aeruginosa are rare causes of septic arthritis and usually occur secondary to a primary focus of infection. Septic arthritis commonly occurs in joints that are anatomically damaged, as in this case with prior rheumatoid arthritis. Any time a patient with arthritis develops a monoarticular flare out of proportion to the other joints, septic arthritis must be suspected.
A 66-year-old man complains of a 1-year history of low back and buttock pain that worsens with walking and is relieved by sitting or bending forward. He has hypertension and takes hydrochlorothiazide but has otherwise been healthy. There is no history of back trauma, fever, or weight loss. On examination, the patient has a slightly stooped posture, pain on lumbar extension, and has a slightly wide based gait. Pedal pulses are normal and there are no femoral bruits. Examination of peripheral joints and skin is normal. What is the most likely cause for this patient’s back and buttock pain?
Lumbar spinal stenosis is a frequent cause of back pain in the elderly. Patients typically have pain that radiates into the buttocks (and sometimes thighs) and is aggravated by walking and by lumbar extension. Decreased vibratory sensation and a wide based gait may also be seen. Narrowing of the spinal canal is usually caused by age-related degenerative changes. A recent randomized controlled trial demonstrated that surgery was more effective than medical therapy in the relief of symptoms for patients with lumbar spinal stenosis. Symptoms often recur several years after surgery. Disc herniation and facet joint arthropathy usually cause unilateral radicular symptoms. Leg pain associated with walking can also be caused by vascular disease, but the symptoms often are unilateral and usually occur in the distal leg. Normal pedal pulses and the classic history make vascular claudication an unlikely diagnosis in this patient. The bone pain of metastatic cancer is rarely positional and is usually unremitting, causing pain both day and night.
A 60-year-old man complains of pain in both knees coming on gradually over the past 2 years. The pain is relieved by rest and worsened by movement. The patient is 5 ft 9 in tall and weighs 210 lb. There is bony enlargement of the knees with mild warmth and small effusions. Crepitation is noted on motion of the knee joint bilaterally. There are no other findings except for bony enlargement at the distal interphalangeal joint. Which of the following is the best way to prevent disease progression?
The clinical picture of pain in weight-bearing joints made worse by activity is suggestive of degenerative joint disease, also called osteoarthritis. Osteoarthritis may have a mild to moderate inflammatory component. Crepitation in the involved joints is characteristic, as is bony enlargement of the DIP joints. In this overweight patient, weight reduction is the best method to decrease the risk of further degenerative changes. Aspirin, other NSAIDs, or acetaminophen can be used as symptomatic treatment, but these agents do not affect the course of the disease. The long-term use of NSAIDs is limited by potential side effects, including renal insufficiency and gastrointestinal bleeding. Calcium supplementation is relevant for osteoporosis, but does not treat osteoarthritis. Oral prednisone would not be indicated. Intra-articular corticosteroid injections may be given two to three times per year for symptom reduction. Knee replacement is the treatment of last resort, usually when symptoms are not controlled by medical regimens and/or activities are severely limited.
A 22-year-old man develops the insidious onset of low back pain improved with exercise and worsened by rest. There is no history of diarrhea, conjunctivitis, urethritis, rash, or nail changes. On examination, the patient has loss of mobility with respect to lumbar flexion and extension. He has a kyphotic posture. A plain film of the spine shows sclerosis of the sacroiliac joints. Calcification is noted in the anterior spinal ligament. Which of the following best characterizes this patient’s disease process?
Insidious back pain occurring in a young male and improving with exercise suggests one of the spondyloarthropathies— ankylosing spondylitis, reactive arthritis (including Reiter syndrome), psoriatic arthritis, or enteropathic arthritis. In the absence of symptoms or findings to suggest one of the other conditions and in the presence of symmetrical sacroiliitis on x-ray, ankylosing spondylitis is the most likely diagnosis. Acute lumbosacral strain would not be relieved by exercise or worsened by rest. The prognosis in ankylosing spondylitis is generally good, with only 6% dying of the disease itself. While pulmonary fibrosis and restrictive lung disease can occur, they are rarely a cause of death (cervical fracture, heart block, and amyloidosis are leading causes of death as a result of ankylosing spondylitis). Rheumatoid factor is negative in all the spondyloarthropathies. Crohn disease can cause an enteropathic arthritis, which may precede the gastrointestinal manifestations, but this diagnosis is far less likely in this case than ankylosing spondylitis.
A 20-year-old woman has developed low-grade fever, a malar rash, and arthralgias of the hands over several months. High titers of anti-DNA antibodies are noted, and complement levels are low. The patient’s white blood cell count is 3000/µL, and platelet count is 90,000/µL. The patient is on no medications and has no signs of active infection. Which of the following statements is correct?
The combination of fever, malar rash, and arthritis suggests systemic lupus erythematosus (SLE), and the patient’s thrombocytopenia, leukopenia, and positive antibody to native DNA provide more than four criteria for a definitive diagnosis. Other criteria for the diagnosis of lupus include discoid rash, photosensitivity, oral ulcers, serositis, renal disorders (proteinuria or cellular casts), and neurologic disorder (seizures). High-dose corticosteroids would be indicated for severe or life-threatening complications of lupus such as described in item a. The arthritis in SLE is nondeforming. Patients with SLE have an unpredictable course. Few patients develop all signs or symptoms. Neuropsychiatric disease occurs at some time in about half of all SLE patients and Raynaud phenomenon in about 25%. Pregnancy is relatively safe in women with SLE who have controlled disease and are on less than 10 mg of prednisone.
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