Differential Diagnosis for Unilateral Lumbar Pain on Percussion
- Single most likely diagnosis
- Pyelonephritis or kidney infection: This condition often presents with unilateral flank or lumbar pain, which can be exacerbated by percussion due to the inflammation of the kidney.
- Other Likely diagnoses
- Musculoskeletal strain: Strain in the lumbar muscles or ligaments can cause localized pain that worsens with movement or percussion.
- Nephrolithiasis (kidney stones): While kidney stones can cause severe, colicky pain, they might also present with more constant pain that is exacerbated by percussion, especially if the stone is causing an obstruction.
- Lumbar disc herniation: A herniated disc can cause localized pain in the lumbar region, which might be worsened by percussion due to the pressure on the surrounding nerves.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Renal cell carcinoma or other kidney tumors: Although less common, tumors of the kidney can cause persistent pain and might be exacerbated by percussion.
- Pneumonia or lung abscess: In rare cases, lower lobe pneumonia or a lung abscess can refer pain to the lumbar region, which could be worsened by percussion due to the involvement of the diaphragm or pleura.
- Aortic aneurysm or dissection: An expanding aortic aneurysm or a dissection can cause severe back pain, which might be unilateral and could potentially worsen with percussion, although this is less typical.
- Rare diagnoses
- Osteomyelitis of the spine: Infection of the vertebral bodies can cause localized pain that worsens with percussion.
- Spinal epidural abscess: A collection of pus in the epidural space surrounding the spinal cord can cause severe back pain, which might be exacerbated by percussion.
- Retroperitoneal fibrosis: A rare condition characterized by the proliferation of fibrous tissue in the retroperitoneum, which can encase and obstruct structures like the ureters, leading to pain that could potentially worsen with percussion.