Tick-borne illnesses are on the rise, and individuals must be especially cautious, utilizing preventative measures during summer and fall months. There are many types of tick-borne diseases such as anaplasmosis, babesiosis, Lyme disease, Rocky Mountain spotted fever, tularemia, ehrlichiosis, and many more. Lyme disease is the most commonly recognized tick-borne illness, with about 300,000 cases diagnosed per year in the United States. Over half of patients diagnosed with a tick-borne illness do not recall experiencing a tick bite, highlighting the importance of preventative measures.
In the United States, the geographic location is an important determinant for which type of tick-borne disease an individual is most at risk for contracting. There are 7 common types of ticks found throughout the United States. The geographic location and type of tick influence the most likely tick-borne illness. The CDC provides a map detailing the different types of ticks, their geographic locations, and their most commonly transmitted diseases.
Signs and symptoms of tick-borne illness vary based upon the etiologic pathogen. Many patients experience fever, rash, and joint pain.
- Most patients with Lyme disease have a characteristic circular rash called erythema migrans that evolves within 3-30 days after a tick bite.
- Up to 60% patients with Rocky Mountain spotted fever have a rash that begins 2-5 days after the onset of fever, and can vary greatly from person to person. It typically begins as a macular rash that begins on the extremities and spreads to the trunk. The rash then becomes more petechial after about day 6.
- About 30% of patients with ehrlichiosis develop a maculopapular or petechial rash.
- Patients with tularemia may develop a skin ulcer at the site of the tick bite with associated lymph node swelling.
Treatment varies depending on the type of tick-borne illness being treated and the extent of disease, with more extreme cases requiring hospitalization and IV antibiotics.
Read more about tick-borne illness in:
CURRENT Diagnosis & Treatment: Family Medicine, 4e: Chapter 53: Tickborne Disease