A mnemonic for remembering the symmetric vs. asymmetric causes of sacroiliitis is:
- P: psoriatic arthritis
- A: ankylosing spondylitis
- I: inflammatory bowel related
- R: reactive (e.g. Reiter syndrome)
The outside letters P & R (letters are far apart) are the asymmetric causes and the inside letters A & I (letters are close together) are the symmetric causes.
- The mnemonic was developed by Dr. Joe Donahue.