Infectious Causes of Low Back Pain
**List of Red Flags indicative of possible spinal pathology**
Vertebral Osteomyelitis
Vertebral osteomyelitis (may also be referred to as: spinal osteomyelitis, spondylodiskitis, septic diskitis, or disk-space infection), is defined as infection of the intervertebral disc and bone of adjacent vertebrae. Vertebral osteomyelitis is an uncommon disease, with an incidence estimated at 2.4 cases per 100,000; however, due to an aging population and increased nosocomial bacteremia exposure (staphylococcus aureus, often methicillin-resistant [MRSA], is the most common causative organism), vertebral osteomyelitis is occurring more frequently in patients of all ages. Predisposing factors for vertebral osteomyelitis include being male and over 50 years of age, more than 50% of vertebral osteomyelitis cases involve persons over the age of 50, with a male-female ratio of 2:1.
Back pain, often accompanied by stiffness, is the most common initial symptom of vertebral osteomyelitis, with the location of pain dependent on the site of the infection. The lumbar spine is the most common site of infection and resultant back pain, with the 1st and 2nd lumbar vertebrae being the most commonly affected vertebral levels (followed by thoracic spine sites and least commonly, cervical spine sites). Vertebral osteomyelitis related back pain is unrelated to movement or position, and is usually localized and continuous, with pain level being anywhere from mild for some, to excruciating for others. Less frequently pain is described as throbbing, intermittent and or radiating (unless nerve roots are involved). Additionally, cervical osteomyelitis, more common among intravenous drug users, may present with: occipital pain, dysphagia and sore throat. While more distal spine involvement may result in shoulder, chest, abdominal hip and or leg pain and patients with spinal cord injuries (paraplegics and quadriplegics) may not experience any pain. It is important for clinicians to remember that the presenting signs and symptoms of vertebral osteomyelitis can vary considerably with each patient case. An acute case of vertebral osteomyelitis may have intense pain and tenderness over the involved vertebra, high fever and systemic toxicity; while a chronic case may not present with pain or fever.
Vertebral osteomyelitis can be classified as: acute, subacute or chronic. Acute osteomyelitis usually develops within two weeks of disease onset, (infection onset or injury), and is seen predominantly in children with hematogenously spread osteomyelitis. Subacute osteomyelitis develops within a few months and chronic osteomyelitis after a few months; however, both subacute and chronic vertebral osteomyelitis are most commonly seen in adults, usually after experiencing an open injury to bone and surrounding soft tissues. Vertebral osteomyelitis can arise secondary to direct implantation of microbes with trauma, (penetrating wounds, skin breakdown and ulcers, etc.), or surgery or through contiguous spread of infection systemically and or from adjacent sites (UTI and respiratory are two very common sources).
Back pain, often accompanied by stiffness, is the most common initial symptom of vertebral osteomyelitis, with the location of pain dependent on the site of the infection. The lumbar spine is the most common site of infection and resultant back pain, with the 1st and 2nd lumbar vertebrae being the most commonly affected vertebral levels (followed by thoracic spine sites and least commonly, cervical spine sites). Vertebral osteomyelitis related back pain is unrelated to movement or position, and is usually localized and continuous, with pain level being anywhere from mild for some, to excruciating for others. Less frequently pain is described as throbbing, intermittent and or radiating (unless nerve roots are involved). Additionally, cervical osteomyelitis, more common among intravenous drug users, may present with: occipital pain, dysphagia and sore throat. While more distal spine involvement may result in shoulder, chest, abdominal hip and or leg pain and patients with spinal cord injuries (paraplegics and quadriplegics) may not experience any pain. It is important for clinicians to remember that the presenting signs and symptoms of vertebral osteomyelitis can vary considerably with each patient case. An acute case of vertebral osteomyelitis may have intense pain and tenderness over the involved vertebra, high fever and systemic toxicity; while a chronic case may not present with pain or fever.
Vertebral osteomyelitis can be classified as: acute, subacute or chronic. Acute osteomyelitis usually develops within two weeks of disease onset, (infection onset or injury), and is seen predominantly in children with hematogenously spread osteomyelitis. Subacute osteomyelitis develops within a few months and chronic osteomyelitis after a few months; however, both subacute and chronic vertebral osteomyelitis are most commonly seen in adults, usually after experiencing an open injury to bone and surrounding soft tissues. Vertebral osteomyelitis can arise secondary to direct implantation of microbes with trauma, (penetrating wounds, skin breakdown and ulcers, etc.), or surgery or through contiguous spread of infection systemically and or from adjacent sites (UTI and respiratory are two very common sources).
Risk Factors
-Intravenous drug use
-Corticosteroid drug use
-Use of immunosuppressive medications
-History of: pneumonia, UTI or skin infection
-History of bloodstream infections (i.e. endocarditis,
bacteremia, fungemia)
-HIV and other immunosupressive disorders
-Pulmonary tuberculosis
-Diabetes
-Adenopathy
-Cancer
-Blunt spinal trauma
-Spinal cord injury with neurogenic bladder
-Spine or disc surgery
-Renal failure requiring hemodialysis
-Use of indwelling intravenous catheters
-Diarrhea
-Recent hospitalization
-Recent history of bacterial infection
-Alcoholism
-Malnutrition
-Advanced age & debilitation
-Corticosteroid drug use
-Use of immunosuppressive medications
-History of: pneumonia, UTI or skin infection
-History of bloodstream infections (i.e. endocarditis,
bacteremia, fungemia)
-HIV and other immunosupressive disorders
-Pulmonary tuberculosis
-Diabetes
-Adenopathy
-Cancer
-Blunt spinal trauma
-Spinal cord injury with neurogenic bladder
-Spine or disc surgery
-Renal failure requiring hemodialysis
-Use of indwelling intravenous catheters
-Diarrhea
-Recent hospitalization
-Recent history of bacterial infection
-Alcoholism
-Malnutrition
-Advanced age & debilitation
Signs and Symptoms
-Pain and local tenderness over the involved spinous
process(es)
-Possible swelling, redness and warmth in the affected
area (signs of inflammation are highly variable)
-Night pain
-Stiff back (increased difficulty with weight bearing,
moving, walking, etc.)
-Paravertebral muscle guarding or spasm
-Positive straight leg raise (SLR) *(Found in 15% of
cases)
-Hip pain (if infection spreads to the psoas muscle)
-Possible constitutional symptoms, such as: fever,
chills, sweats, extreme fatigue and malaise
-Anorexia
-Possibly signs and symptoms associated with nerve
root and or spinal cord involvement *(Found in 20-40%
of cases)
-Elevated erythrocyte sedimentation
process(es)
-Possible swelling, redness and warmth in the affected
area (signs of inflammation are highly variable)
-Night pain
-Stiff back (increased difficulty with weight bearing,
moving, walking, etc.)
-Paravertebral muscle guarding or spasm
-Positive straight leg raise (SLR) *(Found in 15% of
cases)
-Hip pain (if infection spreads to the psoas muscle)
-Possible constitutional symptoms, such as: fever,
chills, sweats, extreme fatigue and malaise
-Anorexia
-Possibly signs and symptoms associated with nerve
root and or spinal cord involvement *(Found in 20-40%
of cases)
-Elevated erythrocyte sedimentation
As a result of the nonspecific and variable nature of many of the signs and symptoms of vertebral osteomyelitis, in addition to the frequent absence of fever, the diagnosis of vertebral osteomyelitis is often delayed significantly after the onset of infection or missed altogether. A delayed or missed diagnosis of vertebral osteomyelitis may result in serious consequences, including: abscesses (paravertebral, epidural, and or psoas), vertebral collapse and kyphosis, gibbous deformity, subluxation, nerve root injury, paraparesis, paraplegia and or aortic infection. Once vertebral osteomyelitis is suspected, diagnosis can be confirmed with radiograph, MRI, and or CT scan imaging.
Disc Space Infection
Disc space infections, (also referred to as discitis or diskitis and in cases involving inflammation of one or more vertebrae, the condition is referred to as spondylodiscitis), are a subacute form of osteomyelitis involving the vertebral endplates and intervertebral disc of one or more vertebral segments of the spine. In discitis, an intervertebral disc becomes infected or inflamed, which can lead to destruction of the adjoining vertebral endplates. Discitis can occur in both children and adults, but is more common in children and rare in older adults. The most commonly affected sites are the lower thoracic and lumbar spine, particularly the lower lumbar levels. Potential causes and routes of infection are often similar to those described under Vertebral Osteomyelitis; most commonly discitis arises from an infection, (bacterial, viral or inflammatory), in another part of the body and spreads to the spine through the bloodstream. For children under the age of 4 years, low-grade viral or bacterial infections are most commonly the cause of discitis; thus, inquiry as to any signs of recent infection, (sore throat, cold, ear infection or other upper respiratory illness), should be made by clinicians. Rarely, infection may spread from bone to disk, (the reverse order of infection spread typically seen in discitis), like in cases involving tuberculosis. Patients undergoing discectomy are at increased risk of developing discitis; postoperative symptoms of a disc space infection usually occur 2 to 8 weeks after discectomy.
Risk Factors
-Recent discectomy
-Recent low-grade viral or bacterial infection (i.e. gastroenteritis, upper respiratory infection, etc.)
-UTI with or without instrumentation (i.e. catherization
or cytoscopy)
-Tuberculosis
-See risk factors associated with increased infection
susceptibility listed under Vertebral Osteomyelitis
-Recent low-grade viral or bacterial infection (i.e. gastroenteritis, upper respiratory infection, etc.)
-UTI with or without instrumentation (i.e. catherization
or cytoscopy)
-Tuberculosis
-See risk factors associated with increased infection
susceptibility listed under Vertebral Osteomyelitis
Signs and Symptoms
For Adults:
-LBP localized around the disc area
-Pain ranging from mild to excruciating (may be
described as "knifelike")
-In cases of severe pain, pain will be constant day & night and movement will be restricted
-Pain worse with activity
-Pain NOT relieved by rest *(unlike with other causes
of LBP)
-In chronic cases, neurological sequale may arise due
to spinal abscess,including pain radiating into the
abdomen, pelvis and/or lower extremities
-Fever
-Raised inflammatory markers
For Children:
-History of increasingly severe localized back pain
-Recent history of: sore throat, cold, ear infection or
other upper respiratory illness
-Refusal to walk, stand or sit (in younger children)
-Pain in back, abdomen, hip and or leg (in older
children)
-Presence of a limp
-Restricted lumbar motion
-Alteration in spinal configuration (increased or
decreased lumbar lordosis, kyphosis or scoliosis)
-Possible positive SLR
-Limitations with positive SLR or other hip movements
-Negative neurologic screening examination
-Localized palpable tenderness over the involved disc
space
-Paraspinal muscle spasm
-Fever
-Erythrocyte sedimentation rate > 20 mm/hr.
-LBP localized around the disc area
-Pain ranging from mild to excruciating (may be
described as "knifelike")
-In cases of severe pain, pain will be constant day & night and movement will be restricted
-Pain worse with activity
-Pain NOT relieved by rest *(unlike with other causes
of LBP)
-In chronic cases, neurological sequale may arise due
to spinal abscess,including pain radiating into the
abdomen, pelvis and/or lower extremities
-Fever
-Raised inflammatory markers
For Children:
-History of increasingly severe localized back pain
-Recent history of: sore throat, cold, ear infection or
other upper respiratory illness
-Refusal to walk, stand or sit (in younger children)
-Pain in back, abdomen, hip and or leg (in older
children)
-Presence of a limp
-Restricted lumbar motion
-Alteration in spinal configuration (increased or
decreased lumbar lordosis, kyphosis or scoliosis)
-Possible positive SLR
-Limitations with positive SLR or other hip movements
-Negative neurologic screening examination
-Localized palpable tenderness over the involved disc
space
-Paraspinal muscle spasm
-Fever
-Erythrocyte sedimentation rate > 20 mm/hr.
Clinicians should be aware that blood tests may show signs of infection, but are not enough to confirm a diagnosis of discitis. Additionally, radiographs do not show evidence of narrowing disk space(s) and or vertebral abnormalities until at least 2 to 3 weeks after disease onset. If untreated, discitis may: resolve on its own, develop into a chronic low-grade infection or progress to osteomyelitis and or an epidural abscess. A spinal CT scan with a biopsy is the best way to confirm a diagnosis of discitis and guide treatment for patients with suspicious symptoms.
Bacterial Endocarditis
Bacterial endocarditis is defined as inflammation of the inner tissue of the heart, often involving valves, caused by infective bacterium. Bacterial endocarditis frequently initially presents with musculoskeletal symptoms, such as: arthralgia, arthritis, low back pain and myalgias, with low back pain often being a patient’s chief complaint. Research estimates that almost one third of patients with endocarditis have low back pain and that half of all bacterial endocarditis cases present only with musculoskeletal symptoms, (and not any other signs of endocarditis). In addition to a lack of cardiac symptoms, bacterial endocarditis often presents with symptoms that mimic other pathologies, such as a herniated lumbar disc, causing diagnosis of bacterial endocarditis to be difficult. An absence of neurological deficits is a key difference that may help clinicians differentiate bacterial endocarditis from a herniated lumbar disc. Please refer to the additional references linked below for detailed bacterial endocarditis differential diagnosis information.
Additional Resources:
Additional Resources:
- Heffner JE. Extracardiac manifestations of bacterial endocarditis. West J Med. Aug 1979;131(2):85-91.
- Murtagh B, Frazier OH, Letsou GV. Diagnosis and management of bacterial endocarditis in 2003. Curr Opin Cardiol. Mar 2003;18(2):106-110.
- Rangel EB, Atallah AN. Musculoskeletal manifestations of bacterial endocarditis. Sao Paulo Med J. Sep 7 2000;118(5):158-160.
- Snelson C, Cline BA, Luby C. Infective endocarditis: a challenging diagnosis. Dimens Crit Care Nurs. Jan-Feb 1993;12(1):4-16.
Risk Factors
-Advanced age
-Previous diagnosis of heart murmur
-Lack of blood flow and or damage to heart valves
-Patients with prosthetic valves
-Injection drug use
-Previous cardiac surgery
-Recent dental work
-Recent history of invasive diagnostic procedures (i.e.
shunts, catheters, etc.)
-See risk factors associated with increased infection
susceptibility listed under Vertebral Osteomyelitis
-Previous diagnosis of heart murmur
-Lack of blood flow and or damage to heart valves
-Patients with prosthetic valves
-Injection drug use
-Previous cardiac surgery
-Recent dental work
-Recent history of invasive diagnostic procedures (i.e.
shunts, catheters, etc.)
-See risk factors associated with increased infection
susceptibility listed under Vertebral Osteomyelitis
Signs and Symptoms
-Low back pain (pain may be one-sided and limited to
paraspinal muscles)
-Possible positive SLR
-Pain may increase with SLR, coughing or sneezing
-Neurologic deficits usually absent *(key difference
with bacterial endocarditis vs. herniated lumbar disc)
-Decreased ROM
-Spinal tenderness
-Arthralgia
-Arthritis
-Myalgias (diffuse and/or local)
-New or changing heart murmur
-Disc infection
-Splenomegaly
-Fever (of unknown cause)
-Night sweats
-Weight loss
-Coughing
-Osler nodes (on pads of fingers, toes, palms of hands
and soles of feet)
-Petechiae (most commonly around the clavicle, lower
neck, conjunctivae, and hard or soft palate)
-Nail clubbing
paraspinal muscles)
-Possible positive SLR
-Pain may increase with SLR, coughing or sneezing
-Neurologic deficits usually absent *(key difference
with bacterial endocarditis vs. herniated lumbar disc)
-Decreased ROM
-Spinal tenderness
-Arthralgia
-Arthritis
-Myalgias (diffuse and/or local)
-New or changing heart murmur
-Disc infection
-Splenomegaly
-Fever (of unknown cause)
-Night sweats
-Weight loss
-Coughing
-Osler nodes (on pads of fingers, toes, palms of hands
and soles of feet)
-Petechiae (most commonly around the clavicle, lower
neck, conjunctivae, and hard or soft palate)
-Nail clubbing
