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Rocky Mountain spotted fever
Spotted fever
Rocky Mountain spotted fever is a disease caused by a type of bacteria carried by ticks.
Causes
Rocky Mountain spotted fever is caused by the bacteria Rickettsia rickettsii (R. Rickettsii) , which is carried by ticks. The bacteria spread to humans through a tick bite.
Tick
Ticks are bugs that can attach to you as you brush past bushes, plants, and grass. Once on you, ticks often move to a warm, moist place on your body...
In the western United States, the bacteria are carried by the wood tick, and in the eastern U.S. they are carried by the dog tick. Other ticks spread the infection in the southern U.S. and in Central and South America.
Contrary to the name "Rocky Mountain," most recent cases have been reported in the eastern United States, including North and South Carolina, Virginia, Maryland, Georgia, Tennessee, and Oklahoma. Most cases occur in the spring and summer and are found in children.
Risk factors include recent hiking or exposure to ticks in an area where the disease is known to occur. The bacteria are unlikely to be transmitted to a person by a tick that has been attached for less than 20 hours. Only about 1 in 1,000 wood and dog ticks carry the bacteria. Bacteria can also infect people who crush ticks they have removed from pets with their bare fingers.
Symptoms
Symptoms usually develop about 2 to 14 days after the tick bite. They may include:
- Chills and fever
- Confusion
- Headache
- Muscle pain
- Rash -- usually starts a few days after the fever; first appears on wrists and ankles as spots that are 1 to 5 mm in diameter, then spreads to most of the body. About one-third of infected people do not get a rash.
Other symptoms that may occur with this disease:
- Diarrhea
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Light sensitivity
Light sensitivity
Photophobia is eye discomfort in bright light.
ImageRead Article Now Book Mark Article - Hallucinations
- Loss of appetite
- Nausea and vomiting
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Thirst
Thirst
Excessive thirst is an abnormal feeling of always needing to drink fluids.
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Exams and Tests
The health care provider will perform a physical examination and ask about the symptoms.
Tests that may be done include:
-
Antibody titer
by
complement
fixation or immunofluorescence
Antibody titer
Antibody titer is a laboratory test that measures the level of antibodies in a blood sample.
ImageRead Article Now Book Mark ArticleComplement
Complement is a blood test that measures the activity of certain proteins in the liquid portion of your blood. The complement system is a group of pr...
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Complete blood count
(CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of red blood cells (RBC count)The number of white blood cells (WBC count)The tota...
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Kidney function tests
Kidney function tests
Kidney function tests are common lab tests used to evaluate how well the kidneys are working. Such tests include:BUN (Blood urea nitrogen) Creatinin...
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Partial thromboplastin time (PTT)
Partial thromboplastin time (PTT)
Partial thromboplastin time (PTT) is a blood test that looks at how long it takes for blood to clot. It can help tell if you have a bleeding problem...
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Prothrombin time (PT)
Prothrombin time (PT)
Prothrombin time (PT) is a blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot. A related blood test is ...
Read Article Now Book Mark Article - Skin biopsy taken from the rash to check for R. rickettsii
-
Urinalysis to check for
blood
or
protein in the urine
Blood
Blood in your urine is called hematuria. The amount may be very small and only detected with urine tests or under a microscope. In other cases, the...
ImageRead Article Now Book Mark ArticleProtein in the urine
The protein urine dipstick test measures the presence of proteins, such as albumin, in a urine sample. Albumin and protein can also be measured using...
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Treatment
Treatment involves carefully removing the tick from the skin. To get rid of the infection, antibiotics such as doxycycline or tetracycline need to be taken. Pregnant women are usually prescribed chloramphenicol.
Outlook (Prognosis)
Treatment usually cures the infection. About 3% of people who get this disease will die.
Possible Complications
Untreated, the infection may lead to health problems such as:
- Brain damage
- Clotting problems
- Heart failure
- Kidney failure
- Lung failure
-
Meningitis
Meningitis
Meningitis is an infection of the membranes covering the brain and spinal cord. This covering is called the meninges.
ImageRead Article Now Book Mark Article - Pneumonitis (lung inflammation)
- Shock
When to Contact a Medical Professional
Call your health care provider if you develop symptoms after exposure to ticks or a tick bite. The complications of untreated Rocky Mountain spotted fever are often life-threatening.
Prevention
When walking or hiking in tick-infested areas, tuck long pants into socks to protect the legs. Wear shoes and long-sleeved shirts. Ticks will show up on white or light colors better than on dark colors, making them easier to see and remove.
Remove ticks immediately by using tweezers, pulling carefully and steadily. Insect repellent may be helpful. Because far fewer than 1% of ticks carry this infection, antibiotics are not usually given after a tick bite.
References
McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies . 4th ed. Philadelphia, PA:Elsevier Saunders; 2014:chap 212.
Walker DH, Blaton LS. Rickettsia rickettsii and other spotted fever group rickettsiae (Rocky Mountain spotted fever and other spotted fevers). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases . 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 188.
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Rocky mountain spotted fever, lesions on arm - illustration
This is the appearance of the rash of Rocky Mountain Spotted Fever on the hands and forearms. The rash starts on the hands and feet and later spreads to the trunk. It is caused by a bacteria transmitted to humans by a tick bite. (Image courtesy of the Centers for Disease Control and Prevention.)
Rocky mountain spotted fever, lesions on arm
illustration
-
Deer ticks - illustration
Diseases are often carried by ticks, including Rocky Mountain Spotted Fever, Colorado Tick Fever, Lyme disease, and tularemia. Less common or less frequent diseases include typhus, Q-fever, relapsing fever, viral encephalitis, hemorrhagic fever, and babesiosis.
Deer ticks
illustration
-
Ticks - illustration
There are many species of ticks. Of these, a large proportion are capable of carrying disease. Diseases carried by ticks include Lyme disease, Erlichiosis, Rocky Mountain Spotted Fever, Colorado Tick Fever, tularemia, typhus, hemorrhagic fever, and viral encephalitis. (Image courtesy of the Centers for Disease Control and Prevention.)
Ticks
illustration
-
Rocky mountain spotted fever on the arm - illustration
Rocky Mountain Spotted Fever is a disease transmitted to humans by a tick bite. The spots begin as flat (macular) red (erythematous) patches that may bleed into the skin, causing purplish spots (purpura). The disease is named after its characteristic spots. (Image courtesy of the Centers for Disease Control and Prevention.)
Rocky mountain spotted fever on the arm
illustration
-
Tick imbedded in the skin - illustration
This is a close-up photograph of a tick embedded in the skin. Ticks are important because they can carry diseases such as Rocky Mountain spotted fever, tularemia, Colorado tick fever, Lyme disease, and others.
Tick imbedded in the skin
illustration
-
Rocky mountain spotted fever on the foot - illustration
Rocky Mountain spotted fever is caused by the organism Rickettsia rickettsii and is transmitted by a tick bite. It is a serious infection that produces a classical rash in about 90% of infected individuals. This is the typical appearance of the rash. There are many symptoms that affect the entire body (systemic).
Rocky mountain spotted fever on the foot
illustration
-
Rocky mountain spotted fever, petechial rash - illustration
Rocky Mountain spotted fever is a potentially fatal infection transmitted to humans by ticks. This photograph shows the classical appearing rash which often begins on the wrists and ankles, and spreads rapidly towards the center of the body. The rash may also be present on the palms and soles.
Rocky mountain spotted fever, petechial rash
illustration
-
Antibodies - illustration
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Antibodies
illustration
-
Rocky mountain spotted fever, lesions on arm - illustration
This is the appearance of the rash of Rocky Mountain Spotted Fever on the hands and forearms. The rash starts on the hands and feet and later spreads to the trunk. It is caused by a bacteria transmitted to humans by a tick bite. (Image courtesy of the Centers for Disease Control and Prevention.)
Rocky mountain spotted fever, lesions on arm
illustration
-
Deer ticks - illustration
Diseases are often carried by ticks, including Rocky Mountain Spotted Fever, Colorado Tick Fever, Lyme disease, and tularemia. Less common or less frequent diseases include typhus, Q-fever, relapsing fever, viral encephalitis, hemorrhagic fever, and babesiosis.
Deer ticks
illustration
-
Ticks - illustration
There are many species of ticks. Of these, a large proportion are capable of carrying disease. Diseases carried by ticks include Lyme disease, Erlichiosis, Rocky Mountain Spotted Fever, Colorado Tick Fever, tularemia, typhus, hemorrhagic fever, and viral encephalitis. (Image courtesy of the Centers for Disease Control and Prevention.)
Ticks
illustration
-
Rocky mountain spotted fever on the arm - illustration
Rocky Mountain Spotted Fever is a disease transmitted to humans by a tick bite. The spots begin as flat (macular) red (erythematous) patches that may bleed into the skin, causing purplish spots (purpura). The disease is named after its characteristic spots. (Image courtesy of the Centers for Disease Control and Prevention.)
Rocky mountain spotted fever on the arm
illustration
-
Tick imbedded in the skin - illustration
This is a close-up photograph of a tick embedded in the skin. Ticks are important because they can carry diseases such as Rocky Mountain spotted fever, tularemia, Colorado tick fever, Lyme disease, and others.
Tick imbedded in the skin
illustration
-
Rocky mountain spotted fever on the foot - illustration
Rocky Mountain spotted fever is caused by the organism Rickettsia rickettsii and is transmitted by a tick bite. It is a serious infection that produces a classical rash in about 90% of infected individuals. This is the typical appearance of the rash. There are many symptoms that affect the entire body (systemic).
Rocky mountain spotted fever on the foot
illustration
-
Rocky mountain spotted fever, petechial rash - illustration
Rocky Mountain spotted fever is a potentially fatal infection transmitted to humans by ticks. This photograph shows the classical appearing rash which often begins on the wrists and ankles, and spreads rapidly towards the center of the body. The rash may also be present on the palms and soles.
Rocky mountain spotted fever, petechial rash
illustration
-
Antibodies - illustration
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Antibodies
illustration
-
Viral encephalitis
(In-Depth)
-
Lyme disease and related tick-borne infections
(In-Depth)
Review Date: 5/1/2015
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
