From the Guidelines
For high-risk Ixodes spp. bites, a single dose of oral doxycycline within 72 hours of tick removal is recommended over observation. When evaluating a tick bite, prompt removal of the tick is essential, using fine-tipped tweezers to grasp the tick as close to the skin as possible and pull upward with steady pressure. Clean the bite area with soap and water, rubbing alcohol, or an iodine scrub.
Key Considerations
- For most tick bites, observation is sufficient, but prophylactic treatment with a single 200mg dose of doxycycline may be considered if the tick was attached for at least 36 hours, the tick is identified as an adult or nymphal Ixodes scapularis (deer tick), and treatment can be started within 72 hours of tick removal, as supported by the guidelines from the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR) 1.
- Monitor for symptoms of tick-borne illnesses for 30 days, including fever, rash (especially the characteristic bull's-eye rash of Lyme disease), headache, fatigue, muscle/joint pain, or swollen lymph nodes.
- If symptoms develop, seek medical attention promptly.
- Testing for tick-borne diseases immediately after a bite is not recommended as it takes time for antibodies to develop.
- The risk of disease transmission increases with longer attachment time, with most pathogens requiring at least 24-48 hours of attachment to transmit.
- Proper tick identification can help assess risk, as different tick species carry different pathogens, with Ixodes ticks transmitting Lyme disease, Dermacentor ticks carrying Rocky Mountain spotted fever, and Amblyomma ticks associated with ehrlichiosis.
Dosage and Administration
- Doxycycline is given as a single oral dose, 200 mg for adults and 4.4 mg/kg (up to a maximum dose of 200 mg) for children, as recommended by the guidelines 1.
Special Considerations
- Doxycycline is relatively contraindicated for women who are either pregnant or breast-feeding, as well as for children, in which case an alternative antimicrobial, such as amoxicillin, may be considered, as discussed in the guidelines from 2006 1.
From the Research
Tick Bite Workup
- The most common tick-borne disease in the United States is Lyme disease, with approximately 20,000 cases reported annually 2.
- Residents of the coastal Northeast, northwest California, and the Great Lakes region are at highest risk, as well as children and those spending extended time outdoors in wooded areas 2.
- The disease is transmitted to humans through the bite of the Ixodes tick (Ixodes scapularis and Ixodes pacificus), and typically, the tick must feed for at least 36 hours for transmission of the causative bacterium, Borrelia burgdorferi, to occur 2.
Diagnosis and Treatment
- Diagnosis is usually made clinically, and treatment is accomplished with doxycycline or amoxicillin; cefuroxime axetil or erythromycin can be used as an alternative 2, 3.
- Late or severe disease requires intravenous ceftriaxone or penicillin G, and single-dose doxycycline (200 mg orally) can be used as prophylaxis in selected patients 2, 4.
- The efficacy of oral doxycycline, amoxicillin, and cefuroxime axetil for treating Lyme disease has been established in multiple trials, and ceftriaxone is recommended when parenteral antibiotic therapy is recommended 3, 4.
Prevention and Other Tick-Borne Illnesses
- Preventive measures should be emphasized to patients to help reduce risk, including tick bite prevention strategies and basic tick removal recommendations 5.
- Other tick-borne illnesses, such as Rocky Mountain spotted fever, anaplasmosis, ehrlichiosis, tularemia, Powassan virus, and alpha-gal syndrome, should also be considered in the diagnosis and treatment of tick-borne illnesses 5.
- Clinical practice guidelines for the prevention, diagnosis, and treatment of Lyme disease have been developed by a multidisciplinary panel representing the Infectious Diseases Society of America, American Academy of Neurology, and American College of Rheumatology 6.