A 34-year-old man comes to the office due to low back pain and tightness for the past 3 months. The pain is dull, has an aching quality, and has become progressively worse. It is worse late at night and in the early morning hours but improves gradually during the day as he moves around. The patient has had no recent injury. Medical history is unremarkable. He lives with his wife and does not use tobacco, alcohol, or recreational drugs. Temperature is 36.1 C (97 F), blood pressure is 120/76 mm Hg, and pulse is 80/min. Examination shows no tenderness over the lumbar spine or lower extremity weakness. Straight-leg raising test is negative. Which of the following most likely accounts for this patient's symptoms?

Question

A 34-year-old man comes to the office due to low back pain and tightness for the past 3 months.  The pain is dull, has an aching quality, and has become progressively worse.  It is worse late at night and in the early morning hours but improves gradually during the day as he moves around.  The patient has had no recent injury.  Medical history is unremarkable.  He lives with his wife and does not use tobacco, alcohol, or recreational drugs.  Temperature is 36.1 C (97 F), blood pressure is 120/76 mm Hg, and pulse is 80/min.  Examination shows no tenderness over the lumbar spine or lower extremity weakness.  Straight-leg raising test is negative.  Which of the following most likely accounts for this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d2eb_5e2c_bc81_df613418f1f6_MD0003_00 Most acute low back pain is due to mechanical causes (eg, muscle strain, ligamentous sprain); it typically improves with rest and resolves spontaneously over 2-4 weeks. However, this patient has inflammatory back pain, which is characterized by chronic, gradual-onset pain and stiffness that worsens with rest (eg, in the later part of the night) and improves with activity. Inflammatory back pain typically begins at age <40 and is a characteristic feature of spondylarthritis, an inflammatory arthritis of the spine. The most common spondylarthritis is ankylosing spondylitis, which characteristically affects the sacroiliac and apophyseal joints of the axial spine; however, spinal involvement can also occur with psoriatic arthritis, reactive arthritis, and arthritis associated with inflammatory bowel disease. Spondyloarthropathies affect the sites of ligamentous insertion (enthesitis) and eventually destroy articular cartilage, resulting in progressive pain and stiffness. Examination findings are often normal early in the disease course, but patients may show reduced spinal range of motion and tenderness at the sacroiliac joints and at tendon insertion sites (eg, along the vertebrae, hands, insertion of Achilles tendon). (Choice A) Osteomalacia is characterized by decreased mineralization of osteoid. It presents with bone pain and muscle weakness and, over time, can lead to fractures. Back pain due to vertebral deformity or fracture in osteomalacia would likely be worse with activity and better with rest, and osteomalacia is uncommon in young patients without an underlying cause (eg, malabsorption, chronic kidney disease). (Choice C) Ligamentous sprains can often be traced to a specific event or action. Patients typically experience more pain with movement and improvement with rest. Symptoms generally resolve within days to weeks. (Choice D) Lumbar disc degeneration can present with mechanical back pain or lumbosacral radiculopathy (ie, pain radiating below the knee along the sciatic nerve). The pain is typically worse with movement. Atraumatic lumbar disc degeneration is uncommon in young patients. (Choice E) Lumbar spinal stenosis is usually seen in patients age >60 due to degenerative arthritis. The pain, which often radiates to the distal lower extremity, is typically worse when ambulating with the spine extended and relieved with spinal flexion (ie, pseudoclaudication). Educational objective: Inflammatory back pain is characterized by the gradual onset of pain and stiffness that begins at a young age (<40), worsens with rest (eg, at night), and improves with activity. It suggests spondyloarthropathy (eg, ankylosing spondylitis, psoriatic arthritis, reactive arthritis, arthritis associated with inflammatory bowel disease).

A 34-Year-Old Man Comes to the Office Due to Low