In Rocky Mountain Spotted Fever, how does the rash typically progress?

• A. Rash begins on the trunk and moves outward to the limbs.
• B. Rash begins on wrists and ankles and spreads to palms and soles.
• C. Rash begins on the face and spreads downward.
• D. Rash is limited to the extremities and never involves palms or soles.

Answer: (B)

RMSF rash shows a distal-to-proximal progression: it often starts on the wrists and ankles and then spreads toward the trunk, with involvement of the palms and soles as it expands. This pattern reflects the way the rash develops from small-vessel inflammation caused by the infection. A rash that begins on the trunk, or that is limited to the extremities without affecting the palms or soles, doesn’t fit the classic presentation as well. So starting on the wrists and ankles and spreading to the palms and soles is the best description.