RED FLAG signs and symptoms of severe low back pain
What are the RED FLAG signs and symptoms that indicate that a patient’s low back pain may be from a serious cause?
Most low back pain is mechanical in nature and should slowly improve over 2 to 6 weeks. As such, the presence of red flags may not be associated with worrisome pathology in a patient with acute onset back pain, especially if it is improving. Potential exceptions include older age, history of steroid use, trauma, and/or presence of a contusion overlying the site of back pain. In patients presenting with chronic low back pain (≥3 months), however, the presence of red flags may be more concerning for underlying pathology. Obtaining imaging studies and additional work-up on every patient with a red flag sign or symptom is controversial and may lead to costly evaluations for a common condition. As such, clinical judgement should be used on a case-by-case basis. Nonetheless, the following signs and symptoms may raise suspicion for significant underlying pathology:
• Unrelenting pain that is unaffected by change in position and not improved by supine position with hips flexed suggests infection, cancer, or infiltrative lesions.
• Fever, chills, and weight loss suggest infection or cancer.
• If the patient is writhing in pain on the exam table and unable to lie still due to pain, consider retroperitoneal pathology: aortic dissection, nephrolithiasis, pancreatitis, or a ruptured viscus unless drug-seeking behavior or psychogenic factors present.
• Pain and morning stiffness for >30 minutes that is improved with exercise in a patient aged <40 years suggests inflammatory spondyloarthropathy.
• Bilateral radiation of pain, which is progressive, suggests cancer, central disk herniation, or spondyloarthropathy.
• Abnormal neurologic exam: sensory/motor deficit (foot drop); loss of rectal tone; urinary incontinence; saddle anesthesia; Babinski’s sign; or ankle clonus suggests nerve root compression; cancer; or central disk herniation.
• Trauma or sudden onset of pain in a patient with risk factors for osteoporosis.
