Q&A Medicine>>>>>Rheumatology
Question 3#

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?

a. Prostate cancer
b. Ankylosing spondylitis
c. Vertebral osteomyelitis
d. Disk herniation

Correct Answer is C


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.