Differential Diagnosis for Lower Back Pain near Sacroiliac Joint, Widespread Achiness, and Fatigue
- Single most likely diagnosis
- Ankylosing Spondylitis (AS): A chronic inflammatory disease that primarily affects the spine and sacroiliac joints, leading to symptoms like lower back pain, stiffness, and fatigue. The widespread achiness could be due to the systemic nature of the disease.
- Other Likely diagnoses
- Sacroiliitis: Inflammation of the sacroiliac joint, which could be due to various causes including infection, trauma, or autoimmune diseases. This would directly explain the pain near the sacroiliac joint.
- Fibromyalgia: A condition characterized by widespread musculoskeletal pain, fatigue, and tenderness in localized areas. While it doesn't specifically target the sacroiliac joint, the widespread achiness and fatigue are key features.
- Osteoarthritis: A degenerative joint disease that could affect the sacroiliac joint, leading to pain and stiffness in that area. However, it might not fully explain the widespread achiness unless multiple joints are involved.
- Do Not Miss diagnoses
- Septic Sacroiliitis: An infection of the sacroiliac joint, which is a medical emergency requiring prompt antibiotic treatment. It could present with severe pain, fever, and systemic symptoms like fatigue.
- Spinal Epidural Abscess: A collection of pus in the epidural space surrounding the spinal cord, which can cause back pain, fever, and neurological deficits. Early diagnosis is crucial to prevent serious complications.
- Cancer (e.g., Metastatic Disease to the Bone): Although less common, cancer can cause back pain, fatigue, and widespread achiness, especially if multiple bones are involved.
- Rare diagnoses
- Spondyloarthritis (other forms like psoriatic arthritis, reactive arthritis, enteropathic arthritis): These conditions can affect the sacroiliac joints and spine, leading to inflammation and pain, but they are less common than ankylosing spondylitis.
- Osteonecrosis of the Sacroiliac Joint: A rare condition where the bone tissue of the sacroiliac joint dies due to lack of blood supply, leading to pain and potentially widespread achiness if the condition affects other joints as well.