After how long can immunoglobulin be administered after a tick bite? - briefly
The recommended window for administering immunoglobulin after a tick bite is as soon as possible, preferably within 72 hours. Some guidelines permit treatment up to 7 days post‑exposure, though efficacy decreases with time.
After how long can immunoglobulin be administered after a tick bite? - in detail
Immunoglobulin is administered as passive prophylaxis only in specific post‑exposure scenarios, most notably rabies immune globulin (RIG) after a potential rabies exposure. When a tick bite is the source of concern, RIG is indicated only if the tick is known to have fed on a rabid animal or if the bite occurred in a region where rabies transmission by ticks, although extremely rare, cannot be excluded. In such cases, the product must be given as soon as the risk is identified; the optimal window is the same day of exposure, and administration is considered acceptable up to seven days after the incident. Beyond this period, the protective effect of the globulin declines sharply because the virus, if present, would have already entered the nervous system.
Key points for timing and administration:
- Immediate administration (within hours) maximizes neutralization of viral particles at the wound site.
- Maximum acceptable delay: 7 days post‑exposure; after this, efficacy is not guaranteed.
- Dosage: 20 IU/kg body weight, infiltrated around the bite site and the remainder given intramuscularly at a site distant from the vaccine injection.
- Concurrent vaccination: Active rabies vaccine series should start on day 0, regardless of the immunoglobulin timeline.
For tick‑borne bacterial infections such as Lyme disease, anaplasmosis, or ehrlichiosis, immunoglobulin is not part of standard therapy. Antibiotic regimens (e.g., doxycycline) are initiated based on clinical presentation and laboratory confirmation, with no defined time window for immunoglobulin use.
In summary, passive immunization after a tick attachment is limited to rabies prophylaxis, requiring administration as early as possible and no later than one week after the bite. Other tick‑borne diseases rely on antimicrobial treatment rather than immunoglobulin.