From the Guidelines
Blood work is recommended after a tick bite if you develop symptoms or if the tick was attached for more than 24 hours, and should include a 2-tiered serologic analysis for Lyme disease, as well as tests for other tick-borne diseases like ehrlichiosis, anaplasmosis, babesiosis, and Rocky Mountain spotted fever, as outlined in the guidelines by the Infectious Diseases Society of America (IDSA) 1. The standard tests for tick-borne diseases include:
- A complete blood count (CBC)
- Comprehensive metabolic panel
- Specific tests for tick-borne diseases like:
- Lyme disease (2-tiered serologic analysis consisting of an enzyme-linked immunoassay or immunofluorescence assay, followed by reflexive immunoblotting) 1
- Ehrlichiosis (Wright or Giemsa stain of peripheral blood or buffy coat leukocytes, and serology: acute and convalescent IFA titers for Ehrlichia antibodies) 1
- Anaplasmosis (Wright or Giemsa stain of peripheral blood or buffy coat leukocytes, and serology: acute and convalescent IFA titers for Anaplasma antibodies) 1
- Babesiosis (Giemsa, Wright’s, Wright-Giemsa stains of peripheral thin and thick blood smears, and serology: acute and convalescent IFA titers for Babesia antibodies) 1
- Rocky Mountain spotted fever (serology: acute and convalescent IFA for R. rickettsii IgM and IgG antibodies) 1 If you've been bitten by a tick, remove it promptly using fine-tipped tweezers, grasping close to the skin and pulling upward with steady pressure. Clean the bite area with alcohol or soap and water. Monitor for symptoms like fever, rash (especially a bull's-eye pattern), fatigue, headache, muscle/joint pain, or swollen lymph nodes for up to 30 days. If symptoms develop, seek medical attention immediately. Early testing may yield false negatives since antibodies take time to develop, so follow-up testing 4-6 weeks after exposure may be necessary. Prophylactic antibiotics (typically a single 200mg dose of doxycycline) might be prescribed in high-risk areas if the tick was attached for over 36 hours, but this varies by region and risk assessment.
From the Research
Blood Work for Tick Bite
- Blood tests are used to diagnose tick-borne diseases, including Lyme disease, which is the most common vector-borne disease in the United States, with an estimated incidence of 300,000 cases per year 2.
- The currently recommended approach for laboratory support of the diagnosis of Lyme disease is a standard two-tiered (STT) algorithm comprised of an enzyme-linked immunoassay (EIA) or immunofluorescence assay (IFA), followed by Western blotting (WB) 2.
- Modified two-tiered (MTT) algorithms have been shown to improve the sensitivity of the testing in early disease while maintaining high specificity 2.
- Testing patient-retrieved ticks for infections is not recommended 3.
- Prophylactic treatment after tick exposure in patients without symptoms is generally not recommended but may be considered within 72 hours of tick removal in specific patients at high risk of Lyme disease 3.
Diagnosis and Treatment
- Lyme disease presents with an erythema migrans rash in 70% to 80% of patients, and treatment may be initiated based on this finding alone 3.
- Doxycycline is the primary treatment option for Lyme disease; however, several concerns are associated with high-dose doxycycline treatment, including the potential to kill beneficial bacteria and produce unwanted off-target effects in eukaryotic cells 4.
- Piperacillin has been identified as a potential alternative treatment for Lyme disease, which can eradicate B. burgdorferi at low-nanomolar concentrations without affecting the murine microbiome 4.
Prevention and Education
- Counseling patients on the use of protective clothing and tick repellents during outdoor activities can help minimize the risk of infection 3.
- Tick bites can potentially be prevented by covering the body as much as possible or by applying repellents to the body and permethrin to clothes 5.
- Many providers evaluate patients for tick bites and treat patients for Lyme disease, but knowledge about appropriate testing is low, and providers may benefit from tailored education about appropriate Lyme disease diagnosis, testing, and effective tick-bite prevention 6.