Dustin Taliaferro

A 30-year-old male presents with intense left forearm pain after cleaning an aquarium at his job 20 minutes prior to arrival. He is unsure what kind of fish were in the aquarium. Physical exam reveals a patient who appears uncomfortable holding his left arm. There is a 5 cm area of erythema to his anterior forearm that is warm to the touch. What is the diagnosis and the best next step in management?