Colorado Tick Fever: Care Instructions

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The Colorado tick is found in Arizona, New Mexico, Nevada, California Colorado, Utah, Wyoming, Idaho, Montana, Oregon, Washington, British Columbia, Alberta, and Saskatchewan


Colorado tick fever is caused by a virus that you get from a tick bite. Some people remember getting a bite. Others don't. The symptoms usually start about 1 to 14 days after you get the tick bite. Symptoms include muscle aches, fever, chills, and headache. Sometimes the fever goes away for a few days and then comes back. Some people also notice that they are sensitive to light.

The illness usually gets better in about a week. But some people may feel tired and weak for a month or two. Treatment can reduce the symptoms. Most people with the illness have mild symptoms and recover completely.

Colorado tick fever occurs in the mountain regions of the western United States and Canada. The tick that carries the virus is the Rocky Mountain wood tick (Dermacentor andersoni). It is found at an elevation of 4,000 to 10,000 feet.

Do not donate blood or bone marrow for 6 months after you have been diagnosed with Colorado tick fever. The virus may stay in your blood for several months. If you donate blood or marrow, you may pass the disease to other people.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

How can you care for yourself at home?

Easing symptoms

  • Rest when you feel tired.
  • Ask your doctor if you can take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve). Read and follow all instructions on the label.
  • To prevent dehydration, drink plenty of fluids. Choose water and other clear liquids until you feel better. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase the amount of fluids you drink.


  • When you come in from outdoors, check your body for ticks. Make sure to check your groin, head, and underarms.
  • Cover as much of your body as you can when you work or play in grassy or wooded areas. Wear a hat, a long-sleeved shirt, and long pants with the legs tucked into your socks. Keep in mind that it is easier to spot ticks on light-colored clothes.
  • Use insect repellents with DEET. Do not use these products on your hands, eyes, and mouth.
  • Use products that contain 0.5% permethrin on your clothing and outdoor gear, such as your tent. You can also buy clothing already treated with permethrin.

When should you call for help?

Call your doctor now or seek immediate medical care if:

  • You are confused or can't think clearly.
  • You have a headache or stiff neck.
  • You have a new or worse rash.
  • You have symptoms of infection, such as:
    • Increased pain, swelling, warmth, or redness.
    • Red streaks leading from the area.
    • Pus draining from the area.
    • A fever.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • You are not getting better as expected.

Where can you learn more?

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.