Differential Diagnosis for Sacral Pain
The differential diagnosis for sacral pain is broad and can be categorized into several groups based on the likelihood and potential impact of missing a diagnosis.
- Single Most Likely Diagnosis
- Sacroiliitis: This is often the most common cause of sacral pain, especially in younger individuals. It can be due to inflammatory conditions such as ankylosing spondylitis, psoriatic arthritis, or reactive arthritis. The justification for this being the single most likely diagnosis lies in its prevalence and the common presentation of sacral pain in patients with these conditions.
- Other Likely Diagnoses
- Coccydynia: Pain in the coccyx (tailbone) area, often resulting from a fall or direct trauma to the area. This condition is likely because it directly involves the sacral region and has a clear mechanism of injury.
- Piriformis syndrome: This condition involves the piriformis muscle compressing the sciatic nerve, leading to pain in the sacral area. It's a likely diagnosis due to the anatomical relationship between the piriformis muscle and the sacrum.
- Sacral stress fracture: Common in athletes, especially those involved in sports with repetitive stress on the sacrum. The likelihood of this diagnosis is increased in individuals with a history of such activities.
- Do Not Miss Diagnoses
- Cauda equina syndrome: A serious condition that requires immediate medical attention, characterized by compression of the nerves in the spinal canal, leading to severe pain, numbness, and potentially permanent neurological damage. Missing this diagnosis could result in significant and irreversible harm.
- Sacral osteomyelitis: An infection of the sacrum that can lead to severe complications if not promptly treated. The potential for serious outcomes justifies its inclusion in the "do not miss" category.
- Tumors (primary or metastatic): Although less common, tumors affecting the sacrum can cause significant pain and have a profound impact on the patient's prognosis if not identified and treated appropriately.
- Rare Diagnoses
- Tarlov cysts: Abnormal fluid-filled sacs that can compress nerves and cause pain. They are rare and often found incidentally, making them less likely but still a consideration in the differential diagnosis.
- Sacral insufficiency fractures: More common in older adults with osteoporosis, these fractures can cause significant sacral pain. While not as common as other causes, they should be considered, especially in the appropriate demographic.
- Inflammatory conditions like sacral tuberculosis or brucellosis: These are rare in many parts of the world but can cause sacral pain and should be considered in patients with a relevant travel or exposure history.