Achenbach syndrome is a rare, benign condition that involves swollen and bruised-looking (or “blue”) fingers and toes. It is not connected to other health conditions but may mimic their symptoms.

DEAR DR. ROACH: I’m an 83-year-old male. I eat a plant-based diet, and I exercise at my local YMCA at least three times a week. I’m concerned that my toes and fingers will turn blue daily, in response ...