Running-Associated Swollen Hands (RASH): Post Ambulatory Swollen Hands (POTASH) in a Man Who Completed a Half Marathon.

A 64-year-old man participated in a 13.1-mile half marathon in San Diego, CA on April 23, 2023. The ambient temperature when he started the race was 54°F, which increased to 64°F on his completing the race 3 hours and 58 minutes later. Both of his hands and their digits started swelling after the first hour of running. They progressively became larger during the remainder of the race; a positive fist sign developed and the patient could not close his hands into a fist (Figure 1). Neither pruritus, swelling at any other site, nor angioedema was reported.