The rash associated with RMSF begins as a maculopapular eruption on the wrists and ankles and spreads centripetally to involve the trunk and extremities. In the early phases, the rash may be blanching, nonpruritic, and macular. In many patients, it eventually becomes petechial.
People with RMSF generally present within a week after a tick bite. Physicians must maintain a high index of suspicion for RMSF in patients with:
History of potential tick exposure
Travel to endemic area
Presentation in spring, summer, or fall (although not limited to these seasons)
RMSF should be considered in patients with unexplained febrile illness even if they have no history of a tick bite or travel to an endemic area. Most tick bites are painless and may be in hidden areas of the body. The classic clinical triad of fever, headache, and rash is rarely present during the first 3 days of illness but is much more common by the second week after tick exposure. The absence or delayed appearance of a rash increases the difficulty of diagnosis. The most common symptoms include:
Fever (typically > 102 °F [>38.9 °C])
Headache, frequently severe
Central nervous system symptoms
Adults tend to present with typical symptoms. Fever with relative bradycardia is the rule. In mild, untreated cases, the fever subsides at the end of the second week.
Learn more about the presentation of RMSF.
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Cite this: Michael Stuart Bronze. Fast Five Quiz: Tick Bites - Medscape - Mar 11, 2022.