About RMSF
Rocky Mountain spotted fever (RMSF) is a bacterial infection
that's transmitted to people by tick bites. It occurs most
often in the spring and summer, during months when ticks are active
- between April and early September.
Although RMSF is most common in the southeastern part of the
United States (Virginia, Georgia, and the Carolinas), it occurs in
other states as well. It's relatively rare (about 250-2,000
cases per year in the United States), but can be a
serious disease if
not treated properly
.
The bacteria
Rickettsia rickettsii
that causes RMSF is transmitted by the dog tick (
Dermacentor variabilis
) in the eastern United States and by the wood tick (
Dermacentor andersoni
) in the Rocky Mountain states. On the West Coast, the lone star
tick (
Amblyomma americanum
) also can transmit the bacteria.
RMSF gets its name from the trademark rash it causes - small red
spots and blotches that begin on the wrists, ankles, palms, and
soles. In addition to the rash, the infection can cause fever,
chills, muscle aches, vomiting, and nausea. Typically, RMSF is
treated with antibiotics and patients recover without any
complications. But with late or no treatment, RMSF can cause
serious health problems. If your child has fever, achiness, stiff
neck, or rash and has or may have been bitten by a tick, it's
important to talk with your doctor.
Signs and Symptoms
The symptoms of RMSF typically develop within 1 week of a tick
bite but can take up to 2 weeks to appear. In many cases, the
person doesn't even remember being bitten by a tick.
Symptoms of RMSF usually begin suddenly. There is a high fever -
often 103º Fahrenheit (39º Celsius) to 105º Fahrenheit (40º
Celsius) - with chills, muscle aches, and a severe headache. Eyes
can become red, muscles may feel tender, and there may be abdominal
pain, nausea, vomiting, poor appetite, and fatigue.
The trademark rash of this infection can begin anytime up to 10
days after the fever and headache start, but it most often appears
on the third to fifth day. The rash looks like small red spots or
blotches that begin on the wrists, ankles, palms, and soles. It
spreads up the arms and legs toward the trunk. As the RMSF
infection progresses, the original red spots might start to look
more like bruises or bloody dots or patches under the skin.
Treating Rocky Mountain Spotted Fever
Doctors usually diagnose Rocky Mountain spotted fever based on
enough symptoms to indicate infection. Test results for RMSF can
take a while to be sent to the doctor, so treatment often starts
before the results are available.
RMSF is typically treated with oral or IV antibiotics, depending
on the severity of the infection. Complications may require
prolonged treatment.
Untreated, RMSF can lead to serious health problems, so it's
important to call your doctor promptly if you notice any symptoms
of RMSF, such as:
- high fever
- headache
- chills
- muscle aches
- red eyes
- rash
Without antibiotic treatment, RMSF can lead to health problems
that involve the heart, lungs, and brain. In the most severe case,
it can be fatal.
If your child is recovering from RMSF at home, follow the
doctor's instructions for giving antibiotics. Allow your child
to rest in bed until the fever and other symptoms are gone.
Prevention
RMSF can be prevented by avoiding tick-infested areas, like
woods and tall grasses, brush, shrubs, and low tree branches, and
by taking precautions when spending time outdoors.
When they're playing outdoors, have kids wear light-colored
clothing that makes ticks more visible if they get onto them and,
if it's practical, long-sleeved shirts and long pants. Use an
insect repellant that fends off ticks, being careful to follow the
label instructions. Be sure to use a repellent that contains 10% to
30% concentration of DEET (look for
N,N-diethyl-meta-toluamide).
Not all ticks carry the RMSF bacteria, but it's a good idea
to remove any immediately. The longer a tick stays attached to the
skin, the greater the chance of infection. It usually takes several
hours for a tick to transmit the bacteria that cause RMSF once it
has become attached to the skin.
To remove a dog tick, use tweezers to grasp it by the head (not
just the body) as close to the skin as possible. Pull steadily
until the tick dislodges. Without touching the tick, preserve it in
a jar or plastic bag until you can show it to your doctor.
Disinfect the bite area with alcohol, wash your hands, and call
your doctor.
Since pets can also bring ticks into your home, check their skin
and fur for ticks whenever they have been playing in tick-infested
areas. Follow your veterinarian's advice about collars and
other products that can be used to keep your pet tick-free.
If you have any concerns, talk with your doctor.
Reviewed by:
Joel Klein, MD
Date reviewed: November 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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