|
The tick responsible is
more active in spring and summer.
Children
between 5-9 years are most commonly bitten.
One
reason is that they are more likely to brush against tick
carrying shrubbery and get bitten.
Rocky
Mountain Spotted Fever is related to typhus and caused by
a rickettsia (bacteria-like organism) transmitted by ticks
(in the eastern U.S it is the deer tick, while in the western
U.S it is the wood tick).
The longer a tick is attached the greater the chance of infection.
That
is why daily surveillance (especially for children) when traveling
in tick borne areas is essential. Tucking pant legs into trousers
and insect repellants also help.
Ticks
should be carefully removed to not leave body parts in the
wound.
Symptoms of Rocky Mountain Spotted start 1-2 weeks after the
tick bite and are usually sudden with high fever, chills,
muscle aches, severe headache and vomiting. A crusted, raised,
lump may be at the inoculum (insect bite) with lymph nodes
swollen.
The
characteristic rash of Rocky Mountain spotted fever begins
1-10 days after the onset of fever.
Small red spots begin at the extremities (hands, feet, ankles)
and spread centrally (towards the trunk) while usually sparing
the face.
With
progression these rashes became purpuric (bleeding under the
skin) so that they will not blanch with pressure.
Complications
of this disease can lead to brain, kidney, liver, lung failure,
and death, if untreated. Treatment is with tetracycline or
a suitable alternative.
Diagnosis is on history and collection of symptoms.
Blood
tests take days to develop. It is important to note that although
this rash is typical, not all cases have the rash or it may
be very faint or hard to see, so its absence does not rule
out the disease. Prognosis related to speed of treatment so
an antibiotic may be started without a specific diagnosis
(many of the tick borne diseases have similar treatments).
Different
types of rickettsia cause other spotted fevers and their name
usually tells of their location. Avoidance, diagnosis and
treatment are similar to Rocky Mountain spotted fever, although
the severity of symptoms can vary between them.
Examples are:
- Mediterranean Spotted Fever
- Kenyan Tick Typhus
- African Tick Bite Fever
- Israeli Spotted Fever
- Astrakhan Fever (found in the Caspian sea),
- Siberian Tick Typhus
- Indian Tick Typhus
- Japanese Spotted Fever
- Queensland Tick Typhus
- Flinders Island Spotted Fever (Australia)
Rocky Mountain Spotted Fever Links
CDC http://www.cdc.gov/ncidod/dvrd/rmsf/
http://www.cdc.gov/ncidod/diseases/submenus/sub_rmsf.htm
Dermatology about http://dermatology.about.com/cs/infectionbacteria/a/rmsf.htm
DermAtlas http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=-960590716
|
