Final answer:
The patient with a broken arm should be evaluated first.
Step-by-step explanation:
Based on the information provided, the patient who should be evaluated first is the patient with a broken arm. This patient has a potential fracture and may require immediate medical attention to prevent further damage or complications. In contrast, the other patients' conditions, such as a minor skin rash, hypertension, and a sprained ankle, are less urgent and can be evaluated after the patient with a broken arm.