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Ticks and Diseases

Tick-borne Diseases: The Big Two

A tick bite

Lyme disease often appears as a "bull's-eye" rash around the site on the skin where there has been a tick bite.
Photo: CDC/James Gathany

Lyme disease

Lyme disease is the most common tick-borne disease in the United States. It can cause fever, headaches, fatigue, and a "bull's eye" skin rash. Left untreated, infection can spread to joints, the heart, and the nervous system. Permanent damage to the joints or the nervous system can develop in patients with late Lyme disease.

Lyme disease has different stages. The rash is a key early-stage symptom. This circular red patch usually appears at the bite site 3 to 30 days after the bite. It expands to 5 to 6 inches in diameter, and persists for 3 to 5 weeks. As the rash enlarges, it may take on a "bull's-eye" appearance. In some people this rash never forms.

Other symptoms of early Lyme disease include:

  • muscle and joint aches
  • headache
  • chills and fever
  • fatigue
  • swollen lymph nodes

Other symptoms may not appear until weeks or months after a tick bite occurs. They include:

  • arthritis (usually as pain and swelling in large joints, especially the knee)
  • nervous system abnormalities
  • heart-rhythm irregularities

NIH Research to Results

  • Although Lyme disease can be effectively treated with antibiotics in its early stages, National Institute of Allergy and Infectious Diseases (NIAID) supported research showed that treatment of chronic Lyme disease with antibiotics is not helpful.
  • In 1981, NIAID-funded research was responsible for identifying the bacterium that causes Lyme disease. Since then, the NIAID Lyme Disease Research Program has continued to support research that has continually improved the prevention, diagnosis, and treatment of the disease.

Antibiotics usually cure early stage Lyme disease. If not treated, the disease can cause problems with the joints, heart and nervous system.

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever (RMSF) is a serious disease caused by a tick bite. About 250-1200 cases have been reported annually over the last 50 years. Contrary to its name, more than half the cases of RMSF occur in the mid-Atlantic to southern region of the U.S. Symptoms include sometimes severe, flu-like symptoms, as well as muscle pain. The red-spotted rash usually happens 2 to 5 days after the fever begins. Antibiotics treat the infection. RMSF can be a very severe illness that requires hospitalization.

Read More "Ticks and Diseases" Articles

Bite Fright! / How to Remove a Tick / Tick-borne Diseases: The Big Two

Spring / Summer 2010 Issue: Volume 5 Number 2 Page 25