“Sausgae digits” occur when a finger or toe swells uniformly its whole length, sort of resembling a sausage roll. That may not sound so polite, but it’s a common term for an uncommon physical finding. The formal word is “dactylitis” — the prefix “dactyl-” refers to “digit,” which means either finger or toe in medical-speak.
Sausage digits are found in up to half of patients with Psoriatic Arthritis, and also in Reactive Arthritis, and can be very helpful in diagnosis. I had one patient who’d gone to an ER with a red, hot, swollen knee. Doctors were worried he had a septic hip, gave him IV antibiotics for a few days, but his joint fluid cultures were negative for bacteria. He then saw me, and mentioned his toe. A urine test for chlamydia was positive, clinching the diagnosis of Reactive Arthritis due to the STD.