Table of ContentsView AllTable of ContentsWhat RMSF Looks LikeSymptomsHow RMSF SpreadsWhere Is RMSF Found?Who Is Most at Risk?RMSF vs. Lyme DiseaseDiagnosisCan RMSF Go Away On Its Own?Treatment OptionsLong-Term EffectsPreventionWhen to Go to the ER
Table of ContentsView All
View All
Table of Contents
What RMSF Looks Like
Symptoms
How RMSF Spreads
Where Is RMSF Found?
Who Is Most at Risk?
RMSF vs. Lyme Disease
Diagnosis
Can RMSF Go Away On Its Own?
Treatment Options
Long-Term Effects
Prevention
When to Go to the ER
This article discusses what you need to know about RMSF and signs that you should see a healthcare provider.
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What Does Rocky Mountain Spotted Fever Look Like?
About five to 10 days after atick bite, you might develop a non-itchy rash on your hands, arms, feet, and legs that spreads over the body. In atypical cases, the rash may start on the trunk or be widespread at the onset. In rare cases, there’s no rash at all.
Signs of RMSF rash are:
Rocky Mountain Spotted Fever Symptoms
Symptoms usually begin three to 12 days after the bite of an infected tick. In addition to the rash, these may include:
The rash typically appears on the third to fifth day after the fever but can occur earlier, later, or not at all.
How Rocky Mountain Spotted Fever Spreads
Once RMSF is in your body, the bacterium enters the bloodstream or lymphatic vessels (channels that carry lymphatic fluid and white blood cells through the lymphatic system) and begins to multiply. As it does, it damages cells that line the inside of small blood vessels, along with smooth muscle cells.
Where Is RMSF Most Commonly Found (and When)?
RMSF has been reported in North America, Central America, and South America.It can be found just about anywhere in the United States but is reported most often in:
You can get a tick bite any time of the year when temperatures are warm, but most people are bitten from April through September.
Who Is Most at Risk for Rocky Mountain Spotted Fever?
Outdoor activities, such as camping, hiking, or golfing, in certain areas may raise your risk of contracting atick-borne illness. Living in tick-infested areas and frequent exposure to dogs may also increase risk.
Rocky Mountain Spotted Fever vs. Lyme Disease
Though many symptoms are the same, the rashes look different. The spotted RMSF rash usually starts on wrists, ankles, palms, and soles and then spreads to arms, legs, and trunk. Lyme disease typically presents with abull’s-eye rashat the site of the tick bite. It can take days, weeks, or even months for symptoms to appear.
RMSF and Lyme disease are treated with antibiotics, which can lead to long-term complications. You can get Lyme disease multiple times.Once you get RMSF, you can’t get it again.
What Tests Help Diagnose Rocky Mountain Spotted Fever?
Your provider will likely start with a thorough clinical exam and blood testing. It’s important to report recent travel or suspected insect bites.
The RMSF blood test can help rule out or confirm the diagnosis. This test is also called Rocky Mountain spotted fever antibody test or indirectimmunofluorescenceantibody (IFA) assay for immunoglobulin G (IgG). However,antibodiesmay not be detectable until seven to 10 days after disease onset.
Can Rocky Mountain Spotted Fever Go Away Without Treatment?
RMSF progresses quickly and is potentially fatal, even in healthy people. Without treatment, death can occur within eight days of the start of symptoms.The fatality rate is between 13% and 25%. For those who quickly start on the right therapy, the fatality rate is between 3% and 5%.
Rocky Mountain Spotted Fever Treatment
Treatment within the first five days of illness significantly reduces disease severity and the likelihood of death.Because lab tests take time, your provider may decide to start treatment based on clinical symptoms and a history of tick bites.
The first line of treatment for all age groups is an antibiotic (drug that kills bacteria) calleddoxycycline.Otherantibiotics, such as chloramphenicol, can be used if you can’t take doxycycline. Most people are cured after five to seven days on antibiotics.
Severe complications may require additional treatments and supportive therapies.
Long-Term Effects of Rocky Mountain Spotted Fever
Without treatment, serious complications can occur, such as:
Other health problems may include:
How to Prevent Rocky Mountain Spotted Fever
Ticks can hitch a ride on your clothes, gear, or pets. Once inside, check for ticks. Putting clothes in the dryer on high heat for at least 10 minutes will kill ticks. Washing in cold or warm water will not.
You don’t always feel a tick on your skin, even when itbites, and it can stay attached to your body for days.Removing the tickbefore it bites makes you less likely to get infected.
When checking your body for ticks, be sure to look under the arms, in and around the ears and hair, belly button, back of the knees, between the legs, and around the waist.
Showering can help remove any ticks that aren’t attached to your skin. If you find a tick, use tweezers and grab the tick as close to your skin as you can. Be sure to pull straight up. Twisting can leave the mouth attached. Then clean the area and your hands thoroughly.
A Word From VerywellIt is important to seek antibiotic treatment if you think you may have RMSF because the symptoms can be severe. Wear long sleeves and pants, use insect repellent, and check for ticks after outdoor activities to prevent disease transmission.—JOSEPHINE HESSERT, DO, MEDICAL EXPERT BOARD
A Word From Verywell
It is important to seek antibiotic treatment if you think you may have RMSF because the symptoms can be severe. Wear long sleeves and pants, use insect repellent, and check for ticks after outdoor activities to prevent disease transmission.—JOSEPHINE HESSERT, DO, MEDICAL EXPERT BOARD
It is important to seek antibiotic treatment if you think you may have RMSF because the symptoms can be severe. Wear long sleeves and pants, use insect repellent, and check for ticks after outdoor activities to prevent disease transmission.
—JOSEPHINE HESSERT, DO, MEDICAL EXPERT BOARD
If you remove a tick, but the mouth or head remains attached, leave it and go to an urgent care facility or emergency room (ER) so it can be safely removed. You should also visit the ER if you have redness, swelling, or other signs of infection at the site of thebite.
Other symptoms that may appear within a week or two may also require urgent attention. these include:
Summary
Symptoms include widespread rash and high fever. Without treatment, RMSF can lead to serious complications and can quickly become fatal. In most cases, prompt treatment with antibiotics can cure the infection.
15 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.RMSF: Deadly, but preventable.National Organization for Rare Disorders (NORD).Rocky Mountain spotted fever.Centers for Disease Control and Prevention.Rocky Mountain spotted fever (RMSF). Signs and symptoms.Centers for Disease Control and Prevention.Rocky mountain spotted fever (RMSF). Transmission.Kjemtrup AM, Padgett K, Paddock CD, et al.A forty-year review of rocky mountain spotted fever cases in california shows clinical and epidemiologic changes.PLOS Neglected Tropical Diseases.2022;16(9):e0010738. doi:10.1371/journal.pntd.0011030Centers for Disease Control and Prevention.Rocky mountain spotted fever (mrsf). Prevention.McCollough M.RMSF and serious tick-borne illnesses (Lyme, ehrlichiosis, babesiosis and tick paralysis).Life-Threatening Rashes.2018 Sep 12:215–40. doi:10.1007/978-3-319-75623-3_16Johns Hopkins Medicine.Ticks and Lyme disease.Johns Hopkins Medicine.Rocky mountain spotted fever.Mississippi State Department of Health.Rocky mountain spotted fever.Eickhoff C, Blaylock J.Tickborne diseases other than Lyme in the United States.CCJM.2017;84(7):555-567. doi:10.3949/ccjm.84a.16110Jay R, Armstrong PA.Clinical characteristics of rocky mountain spotted fever in the united states: A literature review.Journal of Vector Borne Diseases. 2020;57(2):114.Harvard Health Publishing.Rocky mountain spotted fever.MedlinePlus.Rocky mountain spotted fever.National Library of Medicine. MedlinePlus.Tick bites.
15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.RMSF: Deadly, but preventable.National Organization for Rare Disorders (NORD).Rocky Mountain spotted fever.Centers for Disease Control and Prevention.Rocky Mountain spotted fever (RMSF). Signs and symptoms.Centers for Disease Control and Prevention.Rocky mountain spotted fever (RMSF). Transmission.Kjemtrup AM, Padgett K, Paddock CD, et al.A forty-year review of rocky mountain spotted fever cases in california shows clinical and epidemiologic changes.PLOS Neglected Tropical Diseases.2022;16(9):e0010738. doi:10.1371/journal.pntd.0011030Centers for Disease Control and Prevention.Rocky mountain spotted fever (mrsf). Prevention.McCollough M.RMSF and serious tick-borne illnesses (Lyme, ehrlichiosis, babesiosis and tick paralysis).Life-Threatening Rashes.2018 Sep 12:215–40. doi:10.1007/978-3-319-75623-3_16Johns Hopkins Medicine.Ticks and Lyme disease.Johns Hopkins Medicine.Rocky mountain spotted fever.Mississippi State Department of Health.Rocky mountain spotted fever.Eickhoff C, Blaylock J.Tickborne diseases other than Lyme in the United States.CCJM.2017;84(7):555-567. doi:10.3949/ccjm.84a.16110Jay R, Armstrong PA.Clinical characteristics of rocky mountain spotted fever in the united states: A literature review.Journal of Vector Borne Diseases. 2020;57(2):114.Harvard Health Publishing.Rocky mountain spotted fever.MedlinePlus.Rocky mountain spotted fever.National Library of Medicine. MedlinePlus.Tick bites.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.RMSF: Deadly, but preventable.National Organization for Rare Disorders (NORD).Rocky Mountain spotted fever.Centers for Disease Control and Prevention.Rocky Mountain spotted fever (RMSF). Signs and symptoms.Centers for Disease Control and Prevention.Rocky mountain spotted fever (RMSF). Transmission.Kjemtrup AM, Padgett K, Paddock CD, et al.A forty-year review of rocky mountain spotted fever cases in california shows clinical and epidemiologic changes.PLOS Neglected Tropical Diseases.2022;16(9):e0010738. doi:10.1371/journal.pntd.0011030Centers for Disease Control and Prevention.Rocky mountain spotted fever (mrsf). Prevention.McCollough M.RMSF and serious tick-borne illnesses (Lyme, ehrlichiosis, babesiosis and tick paralysis).Life-Threatening Rashes.2018 Sep 12:215–40. doi:10.1007/978-3-319-75623-3_16Johns Hopkins Medicine.Ticks and Lyme disease.Johns Hopkins Medicine.Rocky mountain spotted fever.Mississippi State Department of Health.Rocky mountain spotted fever.Eickhoff C, Blaylock J.Tickborne diseases other than Lyme in the United States.CCJM.2017;84(7):555-567. doi:10.3949/ccjm.84a.16110Jay R, Armstrong PA.Clinical characteristics of rocky mountain spotted fever in the united states: A literature review.Journal of Vector Borne Diseases. 2020;57(2):114.Harvard Health Publishing.Rocky mountain spotted fever.MedlinePlus.Rocky mountain spotted fever.National Library of Medicine. MedlinePlus.Tick bites.
Centers for Disease Control and Prevention.RMSF: Deadly, but preventable.
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Centers for Disease Control and Prevention.Rocky Mountain spotted fever (RMSF). Signs and symptoms.
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Kjemtrup AM, Padgett K, Paddock CD, et al.A forty-year review of rocky mountain spotted fever cases in california shows clinical and epidemiologic changes.PLOS Neglected Tropical Diseases.2022;16(9):e0010738. doi:10.1371/journal.pntd.0011030
Centers for Disease Control and Prevention.Rocky mountain spotted fever (mrsf). Prevention.
McCollough M.RMSF and serious tick-borne illnesses (Lyme, ehrlichiosis, babesiosis and tick paralysis).Life-Threatening Rashes.2018 Sep 12:215–40. doi:10.1007/978-3-319-75623-3_16
Johns Hopkins Medicine.Ticks and Lyme disease.
Johns Hopkins Medicine.Rocky mountain spotted fever.
Mississippi State Department of Health.Rocky mountain spotted fever.
Eickhoff C, Blaylock J.Tickborne diseases other than Lyme in the United States.CCJM.2017;84(7):555-567. doi:10.3949/ccjm.84a.16110
Jay R, Armstrong PA.Clinical characteristics of rocky mountain spotted fever in the united states: A literature review.Journal of Vector Borne Diseases. 2020;57(2):114.
Harvard Health Publishing.Rocky mountain spotted fever.
MedlinePlus.Rocky mountain spotted fever.
National Library of Medicine. MedlinePlus.Tick bites.
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