What are the likely causes of a sharp, localized tender point on the lateral thoracic back near the bra line, a few centimeters lateral to the spine, in the absence of fever, skin changes, trauma, or neurological deficits?

Lateral Thoracic Back Pain Near Bra Line: Likely Causes

The most likely cause of sharp, localized tender point pain lateral to the spine near the bra line is myofascial pain or musculoskeletal strain of the thoracic paraspinous soft tissues, which is a common benign condition that typically resolves with conservative management. 1, 2

Primary Differential Diagnosis

Most Likely: Musculoskeletal Causes

Myofascial pain syndrome is the leading diagnosis for this presentation, characterized by:

• Localized tender points (trigger points) in thoracic paraspinous muscles 2
• Sharp pain with direct palpation 3
• Pain lateral to the spine, typically 7-8 cm from midline 4
• Self-limited course responsive to conservative treatment 5

Thoracic facet joint pain should be considered if:

• Pain is aggravated by prolonged standing, hyperextension, or rotation of the thoracic spine 3
• Paravertebral location with point tenderness 3
• No radiating symptoms present 3

Intercostal nerve irritation may present with:

• Sharp, localized pain in the distribution of a thoracic nerve root 3
• Pain that may wrap around the chest wall 6
• Tenderness at specific points along the nerve course 4

Less Common but Important Considerations

Thoracic disc disease is less likely given the lateral location but remains possible:

• Most commonly occurs below T7 level 2, 6
• Typically presents with midline or paravertebral pain rather than far lateral pain 6
• Often associated with radiating pain around the chest (76% of cases) 2
• Frequently calcified and seen in patients aged 30-50 years 2

Red Flags Requiring Urgent Evaluation

You must systematically screen for serious pathology that would change management:

Immediate Life-Threatening (Requires Emergency Evaluation)

• Aortic dissection: Sudden onset, tearing/ripping quality, severe intensity, pulse deficits, blood pressure differential >20 mmHg between arms 1, 5

Serious Pathologies (Require Imaging)

• Compression fracture: Age >65 years, chronic steroid use, known osteoporosis, midline tenderness, significant trauma 1, 2, 5
• Malignancy: Age >50, history of cancer, unexplained weight loss, constant pain unrelieved by rest, night pain 2, 7
• Spinal infection: Fever, recent infection, immunosuppression, IV drug use, constant pain with systemic symptoms 2, 7
• Myelopathy: Radiating numbness/tingling to legs, motor weakness, sensory level, spasticity, bladder dysfunction 7

Clinical Assessment Algorithm

Step 1: Determine Acuteness and Red Flags

• Acute (<4 weeks) without red flags: No imaging indicated 1, 5
• Subacute (4-12 weeks) without red flags: Conservative therapy first-line 5
• Any red flags present: Proceed to imaging 1, 2

Step 2: Neurological Examination

• Check for motor weakness, sensory changes, reflexes, and signs of myelopathy 7
• If myelopathy suspected: Urgent MRI thoracic spine without contrast within 12 hours 7
• If radiculopathy present: MRI thoracic spine without contrast 2

Step 3: Risk Factor Assessment

• Fracture risk (age >65, steroids, osteoporosis): X-ray thoracic spine initially 2, 5
• Malignancy risk (age >50, cancer history, weight loss): MRI with and without contrast 2, 7
• Infection risk (fever, immunosuppression): MRI with and without contrast 2, 7

Step 4: Initial Management for Uncomplicated Cases

Conservative treatment for 4-6 weeks includes:

• Medications per WHO pain ladder 3
• Physical therapy/manual therapy 3
• Activity modification 5
• Reassessment at 4 weeks 5

Imaging Recommendations

For your specific presentation (lateral thoracic pain, point tenderness, no red flags):

• No imaging is indicated initially 1, 5
• Imaging may be considered only after 4-6 weeks of conservative management with no improvement 1
• Exception: If any red flags develop, proceed directly to appropriate imaging 1, 2

Critical Pitfalls to Avoid

Do not miss these scenarios:

• Positional symptoms (pain when transitioning from lying to standing) suggest spinal instability or cord compression requiring urgent MRI 7
• Mid-thoracic tenderness is not normal in asymptomatic individuals; cervical spine is naturally more tender than thoracic region 8
• Young women with thoracic pain may have "benign thoracic pain syndrome" from disc dehydration, though this typically presents with midline rather than lateral pain 6
• Development of neurological symptoms at any point requires immediate MRI evaluation 5, 7

When to Refer

Interventional pain management referral if conservative treatment fails after 6 weeks:

• Pulsed radiofrequency treatment of dorsal root ganglion for radicular pain 3
• Radiofrequency treatment of medial branch for facet pain 3

Urgent neurosurgical consultation if:

• Myelopathy confirmed on MRI 7
• Progressive neurological deficits 7
• Severe intractable pain despite conservative management 7