Differential Diagnosis for Coccydynia

The differential diagnosis for coccydynia, which refers to pain in the coccyx (tailbone) area, can be organized into several categories based on likelihood and potential impact of missing the diagnosis.

• Single Most Likely Diagnosis
  • Coccygeal fracture or contusion: This is often the result of a fall onto the buttocks, direct trauma to the coccyx, or repetitive strain from activities like cycling. The pain is typically localized to the coccyx and may worsen with sitting or standing up from a seated position.
• Other Likely Diagnoses
  • Coccydynia due to childbirth: Women who have experienced a difficult delivery, especially those involving instrumental assistance or a large baby, may develop coccydynia due to trauma to the coccyx during childbirth.
  • Pilonidal sinus or cyst: Although not directly related to the coccyx, a pilonidal sinus or cyst in the nearby area can cause pain that might be mistaken for coccydynia.
  • Levator ani syndrome: This condition involves pain and tenderness in the muscles of the pelvic floor, which can sometimes be confused with coccydynia due to the proximity of the areas.
• Do Not Miss Diagnoses
  • Cauda equina syndrome: A serious condition where the nerves in the spinal canal are compressed, leading to pain, numbness, and potentially severe neurological deficits. Early recognition is crucial to prevent long-term damage.
  • Infection (e.g., osteomyelitis, abscess): Infections in the coccyx area can cause severe pain and have significant consequences if not promptly treated.
  • Tumors: Both benign and malignant tumors can occur in the coccyx, and while rare, missing such a diagnosis could have severe implications.
• Rare Diagnoses
  • Tarlov cysts: These are fluid-filled sacs that can form on the nerve roots in the spine, including near the coccyx, and can cause pain and neurological symptoms.
  • Chordoma: A rare type of bone cancer that can occur at the base of the spine, including the coccyx, and may cause pain and other symptoms.

Each of these diagnoses has a different set of implications for treatment and prognosis, making a thorough evaluation essential for managing coccydynia effectively.