The hallmark spotted rash of Rocky Mountain spotted fever does not appear until day 2 to 5 of illness, and roughly 10 percent of cases never develop a rash at all. Waiting for a rash before starting doxycycline is a leading cause of death from RMSF. Empirical treatment based on tick exposure plus fever is the safer move.
Untreated Rocky Mountain spotted fever kills roughly 20 to 25 percent of patients, with most deaths in the second week of illness.…
Rickettsia parkeri rickettsiosis, transmitted by the Gulf Coast tick, causes fever, headache, and a near-pathognomonic black eschar at the…
Rhipicephalus sanguineus is a competent vector of Rickettsia rickettsii in the southwestern United States and northern Mexico, where…
Dermacentor occidentalis transmits Rickettsia 364D (now classified as Rickettsia rickettsii subsp. californica), the cause of Pacific…
A 2001 NEJM trial by Robert Nadelman and colleagues showed that a single 200 mg oral dose of doxycycline within 72 hours of removing an…
The textbook bullseye rash with central clearing appears in only about 20 to 30 percent of erythema migrans cases. The more common…