A 71-year-old man with a history of hypertension and hyperlipidemia presents with severe left knee pain and fever. Physical examination demonstrates a swollen left knee with limited range of motion. The patient is noted to have a temperature of 38.8°C and a blood pressure of 150/100 mmHg. Synovial fluid is drawn from the left knee and reveals the following.
Which of the following is likely to be present in this patient’s condition?
Calcification of articular cartilage. The patient in this question is showing signs and symptoms of pseudogout, an acute arthritis that is caused by calcium pyrophosphate dihydrate (CPPD) crystal release from calcified articular cartilage into the joint space. This calcification of articular cartilage is referred to as chondrocalcinosis and often manifests with pain, swelling, erythema, fever, and limited range of motion. The knee is the most common joint that is affected in pseudogout (Figure below demonstrates articular cartilage calcification on x-ray).
Of note, even though fever and leukocytosis (often with left shift as seen in this patient) can occur in pseudogout, they are not required for the diagnosis. Diagnosis of pseudogout relies on identifying rhomboidshaped positively birefringent crystals on synovial fluid analysis. An approach to the initial differential diagnosis of arthritis is shown below in Figure below.
(B) Rheumatoid factor (RF) typically occurs in rheumatoid arthritis (RA); however, a positive RF does not make the diagnosis of RA as RF can be positive in several other conditions. RA is characterized by a symmetric arthritis of insidious onset. Fever can be present as well. (C) Tophi are characteristic of gout (specifically chronic gout) and are urate crystals that manifest as yellowish nodules of firm consistency at affected joints (Figure below).
Gout is diagnosed by needle-shaped, negatively birefringent crystals on synovial fluid analysis. (D) S. aureus bacteremia with arthritis would characterize septic arthritis (S. aureus is the most common cause). Even though this patient presents with fever and leukocytosis, the identification of rhomboid-shaped positively birefringent crystals leads to the diagnosis of pseudogout. Furthermore, the gram stain is negative with this patient.
A 68-year-old man presents with pain in his shoulders, hips, and neck for the last 5 months. The patient reports that the pain is worse in the morning and typically resolves within a few hours. The patient is otherwise healthy and denies headache, visual disturbances, or difficulty chewing. Physical examination does not demonstrate swelling and normal range of motion is noted at all joints. Palpation of the scalp arteries fails to elicit tenderness. Laboratory results reveal the following.
Which of the following is the best next step in management for this patient’s condition?
: Low-dose corticosteroids. The patient in this question is presenting with signs and symptoms consistent with a diagnosis of polymyalgia rheumatica (PMR), including chronic pain in the shoulders and hips, morning stiffness, elevated ESR, and age greater than 50. Of note, the physical examination in PMR is usually insignificant and the range of motion is typically normal without any associated tenderness or pain. The treatment of choice for PMR is low-dose prednisone. PMR can be associated with temporal arteritis (also known as giant cell arteritis). (A, C) Symptoms of temporal arteritis include headache, vision loss, tenderness over the temporal artery, and jaw claudication. Since the patient denies these symptoms, temporal arteritis is highly unlikely; therefore, temporal artery biopsy is unnecessary at this time. The treatment for temporal arteritis is immediate high-dose corticosteroids in order to prevent blindness. (D) NSAIDs are helpful in PMR for mild pain or while patients are being tapered off of corticosteroids. However, they are not the first choice in management as they are not as effective as corticosteroids.
A 28-year-old man with a history of asthma presents with worsening lower back pain. He describes the pain as constantly aching and deep. The pain is exacerbated with movement, but not relieved entirely by rest. He is unable to recall any inciting event. Review of systems is otherwise unremarkable. The patient refuses to give a social history. The patient has a temperature of 37°C, blood pressure of 120/80 mmHg, and heart rate of 76 beats per minute. On physical examination, there is exquisite tenderness to gentle percussion over the lumbar vertebral spinous processes. A straight leg test is performed and is normal. Laboratory results are within normal limits except for a significantly elevated erythrocyte sedimentation rate (ESR) of 240 mm/h.
Which of the following is the most likely diagnosis in this patient?
Vertebral osteomyelitis. This patient is presenting with signs and symptoms of vertebral osteomyelitis. The most common pathogen involved in vertebral osteomyelitis is S. aureus and those at risk include IV drug users, sickle cell patients, and immunosuppressed patients. Of note, the physical examination is critical in diagnosing vertebral osteomyelitis as tenderness to gentle percussion over the spinous process of the involved vertebrae is a specific finding. ESR is often elevated in vertebral osteomyelitis. The best initial step in management when vertebral osteomyelitis is suspected is to order an MRI as this is the most sensitive study. Treatment includes long-term IV antibiotics.
(A) This patient is quite young to have prostate cancer. Furthermore, the patient does not endorse any systemic symptoms. The localized pain on palpation is not characteristic of metastatic prostate cancer. (B) Ankylosing spondylitis often occurs in young men, but is characterized by pain and limited range of lower back motion. Symptoms are worse in the morning and localized tenderness to palpation at the vertebrae is not usually present. (D) Disk herniation is highly unlikely given the negative straight leg test and lack of recall of an inciting traumatic event. Also, tenderness to palpation is less likely over the spinous processes in the setting of a disk herniation.
A 46-year-old obese woman with a history of type 2 diabetes mellitus presents with severe left-sided foot pain for the last 6 weeks. The patient has had much difficulty ambulating and has to use a wheelchair now due to the pain. Physical examination demonstrates a severely deformed left foot and x-rays confirm extra-articular bone fragments, varying sizes of osteophytes, and several effusions in the small joints of the left foot.
Which of the following is the underlying mechanism of this patient’s disease?
Nerve damage. This patient is presenting with Charcot joint (neurogenic arthropathy) secondary to diabetic neuropathy. Charcot joint first develops from an inability to detect pain, proprioception, and temperature, which is likely the end result of years of peripheral nerve damage from diabetes. Over time, patients get secondary joint disease and deformation by traumatizing weight-bearing joints. X-ray is diagnostic and reveals osteophytes, loose bone fragments, and cartilage loss. Treatment includes managing the underlying diabetes and offering special shoes for mechanical support and to reduce further trauma. (A) Avascular necrosis (AVN) causes bone destruction from poor vascular supply (not neuropathically mediated). AVN can occur with corticosteroid use, trauma, and autoimmune disease. (C) Uric acid deposition causes gout. It usually affects the big toes and ankles and is severely painful. (D) Charcot joint is not the result of an autoimmune process such as rheumatoid arthritis.
A 43-year-old woman presents with chronic pain that she describes as occurring “all over her body.” Any movement exacerbates the pain and she reports much difficulty falling asleep at night. She constantly feels fatigued, but she denies fever, weight loss, or obvious muscle weakness. The patient has tried acetaminophen to no avail and has even attempted to run 1 to 2 miles per day with no improvement in her symptoms. The patient has an insignificant past medical history. Physical examination is significant for tenderness to palpation over several specific locations on her body. Neurologic examination is unremarkable and laboratory results are all within normal limits.
Given this patient’s most likely diagnosis, which of the following is the best initial treatment?
Amitriptyline. The patient in this question is presenting with signs and symptoms consistent with a diagnosis of fibromyalgia (FM). FM is more common in middle-aged women and is characterized by chronic widespread pain and allodynia (a heightened and painful response to pressure). Physical examination is typically normal except for point muscle tenderness in several areas including the mid-trapezius, lateral epicondyle, and greater trochanter, among others. Of note, FM has no laboratory findings that are diagnostic of the condition. The first-line treatment for FM is patient education, aerobic exercise, and good sleep hygiene. This patient has clearly attempted those recommendations based on the history she provides, so the first-line medication is a tricyclic antidepressant (TCA) such as amitriptyline. Several other drugs (pregabalin and duloxetine) can be attempted if TCAs fail to alleviate the patient’s symptoms. (A, B) Corticosteroids and NSAIDs are useful in treating inflammatory conditions, but FM is not an inflammatory condition (not associated with elevated inflammatory markers such as ESR). (D) Colchicine is useful in treating gout, not FM.
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