Which of the following describes a key symptom of Rocky Mountain spotted fever?

Rocky Mountain spotted fever (RMSF) is characterized by a specific type of rash that develops in its infected patients. The key symptom, a spotted rash, typically initiates at the wrists and ankles before spreading to the trunk and other areas of the body. This rash is often associated with other symptoms such as fever and headache, making it an essential diagnostic criterion.

The rash in RMSF is distinct from other conditions, such as Lyme disease, which is known for the characteristic bull's eye appearance. Additionally, severe muscle cramps are not a hallmark of RMSF, and while fresh tick bites may indicate a potential exposure to disease, they are not considered a symptom of the illness itself. Thus, the presence of a spotted rash on the ankles or wrists effectively identifies a key symptom of Rocky Mountain spotted fever, making it the correct choice.