Atypical presentation of Rocky Mountain Spotted Fever


Rocky Mountain spotted fever (RMSF) is a potentially deadly tick-borne disease which can progress rapidly. An early diagnosis is imperative, since administering treatment within the first 5 days of illness can significantly reduce disease severity and likelihood of fatality, according to Hussain et al.

Rocky Mountain spotted fever was initially identified in the Rocky Mountain region. However, RMSF cases are now reported throughout the nation, with higher incidence in the southeastern and south-central regions.

In their article, “Unconventional Rocky Mountain Spotted Fever Presentation From Kentucky: A Compelling Case Report and Literature Review,” Hussain and colleagues describe the case of a 71-year-old man who was admitted to the hospital with a fever, generalized weakness with myalgia, persistent hiccups, confusion and agitation.¹

A physical exam revealed the patient exhibited tachycardia, tachypnea, elevated blood pressure, and a high fever of 103.3°F. Test results showed severe hyponatremia (an electrolyte abnormality), leukocytosis, and abnormal blood parameters.

Initial treatment for sepsis

The man’s symptoms improved after he was treated with IV ceftriaxone for sepsis due to a urinary tract infection or pneumonia.

However, the patient later developed a 106.5°F fever and was admitted to the ICU.

“Upon further history-taking to determine the source of a fever of unknown origin, the patient revealed a potential exposure to ticks and a cat suspected of having lice one week prior.”

He was subsequently tested for Bartonella, Borrelia burgdorferi, and Rickettsia (the bacterium which causes Rocky Mountain spotted fever).

As a precaution, the patient was treated empirically with doxycycline for a possible tick-borne illness and released from the hospital.

Although initial testing was inconclusive for a tick-borne illness, follow-up testing was positive for Rickettsia.

“This case report underscores the diagnostic challenges posed by atypical presentations of RMSF and emphasizes the critical importance of early detection and treatment to prevent severe complications.”

Rocky Mountain spotted fever – key points:

  • RMSF typically manifests with vague symptoms including fever, headache, rash, muscle pain, and nausea.
  • Test results are often within normal ranges in the early stages of disease. According to the authors, “it may take several weeks to obtain confirmatory diagnostic outcomes.”
  • “Atypical manifestations of RMSF, such as generalized neurologic complaints, myocarditis, or visual disturbances, are not well characterized in the literature. Healthcare providers should consider RMSF in the differential diagnosis of patients with these manifestations.”


  1. Hussain A, Gray C, Marlowe S, et al. (November 09, 2023) Unconventional Rocky Mountain Spotted Fever Presentation From Kentucky: A Compelling Case Report and Literature Review. Cureus 15(11): e48558. doi:10.7759/cureus.48558

2 Replies to "Atypical presentation of Rocky Mountain Spotted Fever"

  • Sadly Jane
    01/15/2024 (3:57 pm)

    I had RMSF and went into psychosis from it. I was placed in an emergency psych facility for a week and my life fell apart as a result. My spouse divorced me and I lost my home and job. Doctors told me to apply for SSDI but I would have been homeless. I also have Hashimotos Encephalopathy so perhaps that triggered an autoimmune attack. I had a petachaie type rash on my chest and torso, stomach problems, myalgia, weakness, fatigue and joint pain, and also random fevers and mental confusion. I have tested positive twice for this despite being on Doxycycline. I now am on the Buehner protocol for it and feel great most days, most symptoms gone. If you think you have Lyme make sure to get on Doxycycline and the Buehner protocols as they will treat RMSF

  • Beth Bacon
    01/15/2024 (5:40 am)

    In my twenties I had Rocky Mountain Spotted Fever from a nymph tick in New Jersey in 1989. It was undiagnosed til I went to a party with an infectious disease doctor who confirmed it. In my fifties I came down with four autoimmune diseases and two connective tissue diseases and now I’m quite sure I’m dealing with a Lysosomal Dusirder, Gaucher or Fabry Diseases as I also have POTS and EDS.

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