An unexpected cause of sacroiliitis in a patient with gout and chronic psoriasis with inflammatory arthritis: a case report.

This case is meant to highlight an important but overlooked cause of active sacroililitis and inflammatory type back pain in patients who have gout, and to bring to the attention that plain X-ray, MRI and ultrasound cannot differentiate between inflammatory sacroiliitis caused by seronegative arthritis versus gouty arthritis. CT scan can add more information but DECT is the preferred method for differentiation and identification of axial tophaceous gout.