FIGURE 66.9 Rocky Mountain spotted fever The rash starts on the wrists and ankles and spreads centripetally (Courtesy of Sidney Sussman In: Arndt KA, Hsu JT, Alam M, et al., eds Manual of Dermatologic Therapeutics 8th ed Philadelphia, PA: Wolters Kluwer; 2014 With permission.) The rash of RMSF begins on the third or fourth day of a febrile illness as a macular or papular eruption on the extremities, most commonly the wrists and ankles ( Fig 66.9 ) Over the next days, the rash spreads typically to the palms and soles as well as centrally to involve the back, chest, and