Tick Diseases: 6 Most Common Illnesses From Tick Bites

Updated in August 2023

Tick diseases are illnesses that are transmitted to people through tick bites. Ticks are small insects that can carry bacteria and viruses, and are commonly found on animals, like dogs, cats and rodents.  

A tick bite can cause a red, round bump on the skin, as well as a fever, chills, headache and muscle aches. Tick diseases are considered to be serious health conditions that require specific treatment to contain infections and prevent organ failure. 

Tick disease diagnosis should be done as early as possible to ensure adequate treatment and resolution. 

Sensitive content
This file may contain unpleasant images that are not suitable for all audiences.
Imagem ilustrativa número 1

List of tick-borne diseases

The most common diseases caused by ticks include: 

1. Lyme disease

Lyme disease is prevalent in the USA and Europe and is caused by the Borrelia burgdorferi bacteria. This bacteria is transmitted to humans through Ixodes species ticks.

Main symptoms: The first signs of Lyme disease can start to manifest up to 30 days after the initial tick bite. Initially, you may notice swelling and redness in the area, followed by a headache, muscle and joint pain, fever, chills, and neck stiffness. 

How to treat: It is important for Lyme disease to be initiated as soon as possible to avoid complications, like neurologic symptoms, heart problems and meningitis. The doctor may prescribe doxycycline twice a day for 4 weeks, or as sufficient. In some cases, the doctor may also recommend physiotherapy to manage physical symptoms.

2. Rocky mountain spotted fever

Rocky mountain spotted fever is a disease caused by the Ricketssia rickettsii bacteria that is transmitted to humans by lone star ticks.  The bacteria is transmitted through a tick bite and enters the blood to circulate throughout the body. For the illness to be contracted, the tick needs to remain in contact with the person for 6 to 10 hours. 

Main symptoms: After the bite, many people will notice red, non-itchy rashes on the wrists and ankles. Other common symptoms include fever over 102ºF, chills, abdominal pain, intense headache and constant muscle pain. 

How to treat: Treatment for rocky mountain spotted fever should be initiated as soon the tick bite is noted, or when symptoms start to emerge. Quick intervention will help to prevent complications. Normally, the doctor will prescribe antibiotics, like cloramphenicol or tetracycline. People with serious cases may be admitted to the hospital for closer monitoring. 

3. Powassan virus

Powassan virus is a rare disease that is transmitted through ticks infected with this virus. Powassan can be transmitted through the same ticks that carry Lyme disease (the Ixodes species), however it differs from Lyme due to its rapid transmission (within minutes, vs days for Lyme disease). 

Main symptoms: Some people may be asymptomatic when infected with the Powassan virus, although others may present with fever, headache, vomiting and weakness. This virus is known to be neuroinvasive, leading to serious signs and symptoms. 

Serious cases are characterized by brain swelling (also known as encephalitis), or inflammation of the tissue that lines the brain and spine (also known as meningitis). The presence of this virus in the nervous system can cause a lack of coordination, confusion, difficulty speaking and memory loss. 

How to treat: There is no specific treatment for Powassan virus, however is it important for infected people to proceed to the hospital to assess the need for admission. Life-threatening cases may require intubation and interventions to reduce brain swelling. 

4. Babesiosis

Babesiosis is an infectious disease that can also be transmitted through ticks that are affected with Babesia spp. 

Main symptoms: Most cases of babesiosis are asymptomatic or present with light symptoms, therefore many people do not know they are even infected. People who have symptoms may notice them up to 4 weeks after the initial tick bite. Symptoms may include feber, headache, chills, cold sweat, muscle pain, excessive fatigue and weakness. 

People over 60 years of age or with a weakened immune system may experience more intense symptoms, like an enlarged liver, enlarged spleen or hemolytic anemia. 

How to treat: Treatment for babesiosis typically involves the use of antiparasitics and/or antibiotics, depending on the present symptoms.

5. Ehrlichiosis

Erlichiosis is a tick disease that is transmitted by ticks infected with Ehrlichia chaffeensis bacteria. This illness affected the blood cells, particularly monocytes and macrophages, and interferes with normal immune system function.

Main symptoms: Symptoms of erlichiosis can emerge up to 12 days after the initial tick bite, leading to fever, headache, chills muscle aches, excessive fatigue, nausea, vomiting and general malaise. 

How to treat: Treatment for erlichiosis normally involves the use of doxycycline as prescribed by a doctor. 

6. Tularemia

Although it is not common, tularemia is also transmitted by tick bites. The ticks that cause this disease are infected with Francisella tularensis bacteria. 

Main symptoms: Symptoms of tularemia can emerge 3 to 14 days after the initial tick bite. It presents with a small skin wound that takes a long time to heal, high grade fever, chills, chest pain, sore throat and general malaise. 

How to treat: Treatment for tularemia should be oriented by a doctor, and usually involves the use of antibiotics for up to 21 days to ensure total bacteria elimination. Adequate treatment can prevent the development of complications and hospital admission. 

How to remove a tick

To remove a tick from the skin, you should follow these steps closely: 

  1. Apply ether or chloroform directly on the tick. 
  2. With a fine-tipped tweezer, pull the tick straight up to prevent parts of the tick remaining in the skin. 
  3. Clean the bite area and wash your hands with soap and water. 

Removing the tick from the skin is fundamental for preventing a serious inflammatory reaction that causes hemolytic anemia, an enlarged spleen or an enlarged liver. It is important to monitor for symptoms like fever, nausea, vomiting, headache, and red rashes, after the tick is removed. You should see a doctor if you notice these in the meantime.

How to prevent tick bites

To prevent tick bites, you should: 

  • Avoid wooded areas, like forests
  • Use tick repellents with DEET, eucalyptus oil, IR2525 or picaridin, which are effective against these parasites
  • Wash your clothes and clean surfaces with products containing permethrin 0.5%.

It is important to inspect pets for ticks periodically. You should wash all clothing in high temperatures following walks in wooded areas.