by Jones P


Ehrlichiosis is an infection passed through a tick bite. It can be deadly unless medicine is taken to treat it.


Ehrlichiosis is caused by specific bacteria. The bacteria are passed through the bite of a tick. The lonestar tick, deer tick, and dog tick are linked with this infection.

Risk Factors

Things that may raise the risk of this infection are:

  • Being in areas known to have ticks
  • Spending time in the Mid-Atlantic, Southeastern, and Southcentral United States
  • Having a weakened immune system


It may take 1 to 2 weeks for symptoms to happen. The first symptoms are like the flu:

  • Fever
  • Chills
  • Muscle and joint aches
  • Headaches

Some people may also have a rash.

Headache and Neck Stiffness
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You will be asked about your symptoms and health history. You will be asked if you have spent time in areas known for ticks. A physical exam will be done.

A blood test may be done to check for signs of ehrlichiosis.


Ehrlichiosis is treated with antibiotics.


To lower the chance of this infection:

  • Avoid tick-infested areas.
  • Wear light-colored clothing to better locate a crawling tick.
  • Tuck pants into socks when in tick-infested habitats.
  • Regularly inspect and remove ticks from the body when in tick-infested habitats.
  • Remove ticks using fine-tipped tweezers by grasping the tick close to the skin’s surface and pulling upward steadily.
  • Disinfect tick bites with soap and water.
  • Use tick repellents.


Centers for Disease Control and Prevention 

Family Doctor—American Academy of Family Physicians 


Health Canada 

Public Health Agency of Canada 


Biggs HM, Behravesh CB, et al. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States. MMWR Recomm Rep. 2016 May 13;65(2):1-44.

Ehrlichiosis. American Academy of Family Physicians website. Available at: Updated September 19, 2017. Accessed November 25, 2019.

Ehrlichiosis. Centers for Disease Control and Prevention website. Available at: Updated January 17, 2019. Accessed November 25, 2019.

Ehrlichiosis and anaplasmosis. EBSCO DynaMed website. Available at: . Updated December 9, 2016. Accessed November 25, 2019.

Revision Information

  • Reviewer: EBSCO Medical Review Board James P. Cornell, MD
  • Review Date: 09/2019
  • Update Date: 05/27/2020