Colorado tick fever is a viral infection spread by the bite of the Rocky Mountain wood tick (Dermacentor andersoni).
Mountain tick fever; Mountain fever; American mountain fever
This disease is usually seen between March and September. Most cases occur in April, May, and June.
Colorado tick fever is seen most often in Colorado, especially in campers. The disease is much less common in the rest of the United States.
Symptoms of Colorado tick fever most often start 3 to 6 days after the tick bite. A sudden fever continues for 3 days, goes away, then comes back 1 to 3 days later for another few days. Other symptoms include:
There are no specific treatments for this viral infection.
The provider will make sure the tick is fully removed from the skin.
You may be told to take a pain reliever if you need it. DO NOT give aspirin to a child who has the disease. Aspirin has been linked with Reye syndrome in children. It may also cause other problems in Colorado tick fever.
If complications develop, treatment will be aimed at controlling the symptoms.
Colorado tick fever usually goes away by itself and is not dangerous.
Call your provider if you or your child develop symptoms of this disease, if symptoms worsen or do not improve with treatment, or if new symptoms develop.
When walking or hiking in tick-infested areas, wear closed shoes, long sleeves, and tuck long pants into socks to protect the legs. Wear light-colored clothing, which shows ticks more easily than darker colors, making them easier to remove.
Check yourself and your pets frequently. If you find ticks, remove them immediately by using tweezers, pulling carefully and steadily. Insect repellent may be helpful.
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.