Andersson lesion in ankylosing spondylitis.

Area of Science:

• Rheumatology
• Orthopedics
• Radiology

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the axial skeleton.
• Vertebral lesions can occur in AS, sometimes presenting with back pain after minor trauma.
• Differential diagnosis of vertebral lesions in AS can be challenging.

Observation:

• A middle-aged male patient presented with acute back pain and a lumbar vertebral lesion after minor trauma.
• Initial imaging (X-ray, MRI) suggested tuberculosis, leading to empirical antituberculous treatment (ATT).
• The patient did not respond to ATT, prompting further investigation.

Findings:

• Re-evaluation revealed the lesion to be an Andersson lesion, a characteristic finding in ankylosing spondylitis.
• The patient's condition improved significantly after discontinuing ATT and initiating management with rest, steroids, methotrexate, and sulfasalazine.
• Histopathological confirmation was not explicitly mentioned, but clinical and radiological response supported the diagnosis.

Implications:

• Awareness of Andersson lesions in AS is critical to prevent misdiagnosis as infections like tuberculosis.
• Characteristic radiological findings on plain spinal X-rays can aid in early and accurate diagnosis.
• Timely diagnosis and appropriate management (e.g., with disease-modifying antirheumatic drugs and supportive care) are essential for favorable outcomes in AS patients with vertebral complications.