What is the test called for a tick bite? - briefly
The diagnostic evaluation for a tick bite is called Lyme disease serology, usually performed with an ELISA test and confirmed by Western blot. This assay detects antibodies to Borrelia burgdorferi to determine infection.
What is the test called for a tick bite? - in detail
The diagnostic procedure most commonly ordered after a suspected tick attachment is a serologic evaluation for Lyme disease, often referred to as Lyme disease antibody testing. This assessment typically includes two stages:
- Enzyme‑linked immunosorbent assay (ELISA) – screens for immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against Borrelia burgdorferi antigens. A positive or equivocal ELISA result prompts confirmatory testing.
- Western blot – distinguishes specific protein bands to verify the presence of antibodies detected by ELISA. Separate criteria exist for IgM (≥2 of 3 bands) and IgG (≥5 of 10 bands) positivity.
When the clinical picture suggests early infection and the bite occurred within the past 24 hours, a polymerase chain reaction (PCR) assay on skin biopsy or blood may be employed to detect Borrelia DNA directly. PCR is also useful for diagnosing co‑infections such as Anaplasma phagocytophilum or Babesia microti.
Additional laboratory markers that support the diagnosis include:
- Elevated erythrocyte sedimentation rate (ESR) or C‑reactive protein (CRP) indicating systemic inflammation.
- Complete blood count (CBC) abnormalities, such as lymphocytosis in early Lyme disease or thrombocytopenia in babesiosis.
Interpretation of results must consider the timing of exposure. Antibody production generally becomes detectable 2–4 weeks after the bite; testing performed earlier may yield false‑negative outcomes. In such cases, clinicians often repeat serology after the appropriate interval.
Treatment decisions are guided by the test findings, the duration of symptoms, and the presence of any co‑infecting pathogens. Prompt identification through the outlined assays reduces the risk of chronic manifestations and facilitates targeted antimicrobial therapy.