Which of the following statements regarding a disseminated rash caused by a tick-borne illness is FALSE?

The statement that the rash typically starts on the trunk is incorrect. In many tick-borne illnesses, such as those caused by Rickettsia rickettsii, which is associated with Rocky Mountain spotted fever, the rash often starts at the extremities, particularly on the wrists and ankles, and then spreads towards the trunk. This is a key characteristic that helps differentiate it from other rashes.

Understanding the typical progression and location of rashes in tick-borne diseases is vital for proper diagnosis and treatment. The other statements provided are true; Rickettsia rickettsii is indeed the causative agent of Rocky Mountain spotted fever, the majority of cases occur in the warmer months from April to September, and untreated infections can lead to high fatality rates.