Rocky Mountain spotted fever is a potentially serious bacterial infection transmitted to humans by tick bites. The illness is named after the Rocky Mountain region, where the disease was first identified. Rocky Mountain spotted fever occurs when an infected tick attaches to your skin and feeds on your blood. The infection then has the potential to spread to your bloodstream and other areas of your body.

Rocky Mountain spotted fever doesn't spread directly from person to person. If treated promptly, a case of Rocky Mountain spotted fever is usually fairly mild. In a small number of people, the disease can be serious, even fatal, especially in older adults. Because Rocky Mountain spotted fever can progress rapidly to a more widespread infection, prompt treatment is important.

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Rash caused by Rocky Mountain spotted fever

Rocky Mountain spotted fever symptoms include:

• High fever — body temperature reaching 102 F (38.9 C) or greater
• Chills
• Severe headache
• Widespread aches and pains
• Restlessness
• Nausea and vomiting
• Loss of appetite
• Fatigue
• A rash of red spots or blotches

Two to 14 days after being bitten by an infected tick, you may develop nausea, headache, loss of appetite and a sore throat. As Rocky Mountain spotted fever develops, fever, chills, tenderness and soreness in your bones and muscles, restlessness, trouble sleeping (insomnia), abdominal pain and vomiting may occur. You may have a cough and, possibly, delirium, lethargy and stupor.

Between the third and fifth day of the fever, a red rash may appear on your wrists, ankles, palms of your hands and soles of your feet. The rash often spreads up your arms and legs to your torso.

A few people who are infected may not develop a rash (Rocky Mountain spotless fever). The absence of a rash does not indicate a milder form of illness, but makes the condition more difficult to diagnose.

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Types of ticks

The cause of Rocky Mountain spotted fever is the organism Rickettsia rickettsii. This bacterium most often is spread to humans by tick bites. Ticks can attach themselves to your skin and feed on your blood. They can lodge anywhere on your body, but often are found in your hair, around your ankles and in your genital area. Once embedded in your skin, ticks can cause a small, hard, itchy lump surrounded by a red ring or halo. The longer an infected tick stays attached to your skin, the greater your chance of acquiring infection.

Rocky Mountain spotted fever also can be transmitted through broken skin, such as a cut or scrape on your hands or fingers. Bacteria that cause this disease circulate in the fluids of a tick's body. If you squeeze or crush a tick as you remove it from yourself, another person or a pet, an infection can occur if the fluid comes in contact with an area of broken skin. It's also possible to develop an infection if you touch your eye after coming into contact with an infected tick.

The culprit ticks
The bacterium that causes Rocky Mountain spotted fever typically is carried by a family of ticks known as Ixodidaeor hard ticks. These ticks live in the low bushes and tall grasses of wooded areas and are more abundant in late spring and early summer.

In the western United States, Rocky Mountain spotted fever is transmitted by the wood tick (Dermacentor andersoni). In the eastern United States, where the disease is most common, it's transmitted by the American dog tick (Dermacentor variabilis). In the southern United States, Central America and South America, Rocky Mountain spotted fever is transmitted by other ticks, such as the lone star tick (Amblyomma americanum) and the brown dog tick (Rhipicephalus sanguineus).

Rocky Mountain spotted fever primarily occurs when ticks are most active and during warm weather when people tend to spend more time outdoors.

Your risk of contracting Rocky Mountain spotted fever depends on what part of the United States you're in, how much time you spend in grassy or wooded areas, and how well you protect yourself. It's important to take precautions against exposure to ticks and to be sure to check yourself and your dog for ticks after being outside.

See your doctor if you develop a rash or become sick after a tick bite. Rocky Mountain spotted fever and other infectious diseases carried by ticks can progress rapidly and may be life-threatening. If possible, take the tick along with you to your doctor's office for laboratory testing.

Your doctor will likely be able to diagnose Rocky Mountain spotted fever by evaluating your signs and symptoms and by conducting a physical examination. In addition, he or she may order a blood test or examine a specimen of the rash or the tick itself to search for the presence of the organism that causes this infection.

If detected in its early stages, Rocky Mountain spotted fever can be most successfully treated with medication. Left untreated, the infection can spread from the site of the bite via your bloodstream, potentially causing infection in other areas of your body. Rocky Mountain spotted fever may cause serious complications involving your joints, heart, lungs, kidneys, and central and peripheral nervous system, such as:

• Heart, lung or kidney failure
• An infection of the membranes and fluid surrounding your brain and spinal cord (meningitis)
• Brain damage
• Problems with blood clotting
• Shock

In a small percentage of cases, Rocky Mountain spotted fever causes death, usually because treatment is delayed or is never sought.

Treatment for Rocky Mountain spotted fever involves careful removal of the tick from your skin and antibiotic medication, such as doxycycline or tetracycline, to eliminate the infection.

Prompt treatment is important because the disease can progress rapidly and may cause serious illness. People who develop Rocky Mountain spotted fever are much more likely to survive if treated within five days of developing symptoms.

How to safely remove a tick
If you find a tick crawling on your skin, carefully remove it. Don't crush it between your fingers. Instead, burn it, bury it or flush it. Be sure to wash your hands afterward.

If a tick has already bitten you and is holding on to your skin, follow these steps:

• Remove the tick by gently grasping it near its head or mouth, preferably with a tweezers.
• Don't squeeze or crush the tick, but pull carefully and steadily.
• Save the tick by sealing it in a plastic bag and storing it in the freezer. This allows the tick to be tested for specific bacteria by your doctor if you become sick from the bite. If no signs or symptoms of infection occur within two weeks after the bite, dispose of the tick by burning it, burying it or flushing it.
• Disinfect the tweezers with alcohol or antibacterial soap and water.
• Wash that area of your skin thoroughly and apply antiseptic to the bite area after the tick has been removed.
• Wash your hands thoroughly.

You can decrease your chances of contracting Rocky Mountain spotted fever by taking some simple precautions:

• Wear long pants and sleeves. When walking in wooded or grassy areas, wear shoes, long pants tucked into socks and long-sleeved shirts. Try to stick to trails and avoid walking through low bushes and long grass.
• Use insect repellents. Products containing DEET (Off! Deep Woods, Repel) or permethrin (Repel Permanone) often repel ticks. Be sure to follow the instructions on the label. Clothing that has permethrin impregnated into the fabric also may be helpful in decreasing tick contact when outdoors.
• Do your best to tick-proof your yard. Clear brush and leaves where ticks live. Keep woodpiles in sunny areas.
• Check yourself and your pets for ticks. Do this after being in wooded or grassy areas. Some ticks are no bigger than the head of a pin, so you may not discover them unless you are very careful.
• Don't assume you're immune. Even if you've had Rocky Mountain spotted fever before, it can occur in the same person more than once. Follow precautions and check yourself for ticks.
• Remove a tick with tweezers. Gently grasp the tick near its head or mouth. Don't squeeze or crush the tick, but pull carefully and steadily. Once you have the entire tick removed, apply antiseptic to the bite area.