Lyme disease is an infection caused by the bacterium Borrelia burgdorferi, which is transmitted to humans through the bite of infected blacklegged ticks. Typical symptoms include fever, headache, fatigue and a characteristic skin rash called erythema migrans. If left untreated, the infection can spread to the joints, heart and nervous system.
Lyme disease diagnosis is based on symptoms, physical findings (such as rash), and the possibility of exposure to infected ticks. Laboratory testing is helpful if used correctly and performed with validated methods. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. Steps to prevent Lyme disease include using insect repellent, removing ticks promptly, landscaping and integrated pest management. When to get tested for Lyme disease depends on the time since the tick bite and if any symptoms are present.
How soon after a tick bite should I get tested?
In most cases, you do not need to rush to get tested for Lyme disease after a tick bite. Here are some general guidelines on when to get tested after a tick bite:
- If the tick was attached for less than 36 hours, testing is not recommended unless symptoms develop later.
- If the tick was attached for 36 hours or more, consider getting tested 3 to 4 weeks after the bite, even if you don’t have symptoms.
- If a rash or possible early Lyme disease symptoms develop, get tested promptly.
- If Lyme disease symptoms like joint pain or neurological issues emerge weeks to months later, get tested at that point.
The incubation period from a tick bite to onset of Lyme disease is typically 3 to 30 days. Only a minority of deer tick bites leads to Lyme disease. Prompt tick removal within the first 24 to 36 hours substantially reduces your risk. Testing too soon after a tick bite is not useful because even if you were infected, your body has not yet produced measurable antibodies.
No testing if tick attached less than 36 hours
If you remove a tick quickly – within about 36 hours – testing for Lyme disease is not recommended at that point. A tick needs to be attached for at least 36 to 48 hours before it can transmit Lyme disease bacteria. The risk is very low if the tick has not been attached long.
Instead, just monitor for potential symptoms of Lyme disease in the following month, such as rash, fever, chills, fatigue, muscle aches or joint pain. If any of those emerge, then get tested promptly. But testing immediately after tick removal is not useful if the tick was attached for less than 36 hours.
Get tested after 36 hours of tick attachment
If a tick was embedded in your skin for 36 hours or more, there is a higher risk that you could get Lyme disease. In this scenario, it’s a good idea to get tested for Lyme disease antibodies even if you don’t have symptoms.
The recommended time frame is to get tested 3 to 4 weeks after the tick exposure. This delay gives your body enough time to generate antibodies that the test can detect. Getting tested any sooner than 3 weeks is not recommended, as false negative results are more likely.
Remember that even with a tick attachment over 36 hours, the risk of getting Lyme disease is still only around 5-10%. But it’s wise to do the Lyme disease blood test as a precaution after this duration of tick exposure. If symptoms emerge, get promptly tested.
Get tested right away if Lyme symptoms appear
If you develop potential symptoms of early Lyme disease, like a fever or unusual rash, get tested for Lyme disease promptly. Do not wait weeks to get tested if Lyme-like symptoms emerge within 3 to 30 days after the tick bite. Common early symptoms include:
- Erythema migrans rash: Occurs in 70-80% of infected people. Expands over a period of days or weeks, often to a large size. May feel warm to the touch but is rarely itchy or painful.
- Flu-like symptoms: Fever, chills, sweats, muscle aches, fatigue, headache, swollen lymph nodes.
- Joint pain: Brief bouts of pain and swelling may come and go in one or more joints.
Any of those symptoms are an indication to get immediate Lyme disease testing after a recent tick bite. You do not have to wait 3 to 4 weeks if you develop symptoms suggestive of early Lyme. The antibodies should be detectable at that point.
Lyme disease testing
Laboratory testing for Lyme disease involves an antibody detection method using blood samples. It looks for antibodies that your immune system produces in response to the Borrelia burgdorferi bacteria.
The standard two-tier test approach is:
- Enzyme immunoassay (EIA) or enzyme-linked immunosorbent assay (ELISA) – This is sensitive screening test that may cross-react with other infections. If positive or unclear, it is followed by…
- Western immunoblot, also called immunoblot – More specific test that is run to confirm positives screened by the ELISA test. Checks for antibodies to particular proteins from the Lyme bacteria.
These Lyme tests have limitations and are susceptible to false results if not used at the right time. Testing should ideally be done 3 to 4 weeks after possible tick exposure, not immediately after. If Lyme symptoms are already present, immediate testing is warranted.
Many people test negative for Lyme disease antibodies in the early weeks after infection, before their immune response has reached detectable levels. This leads to false negative results. If Lyme symptoms emerge, a repeat test may be needed a month later.
On the other side, false positive Lyme test results also occur due to cross-reactivity with antibodies against other bacteria. Any positive result should be confirmed with a Western immunoblot test. Also consider if there are other reasons you may test positive, like an autoimmune disorder.
Other Lyme disease tests
While antibody detection blood tests are standard, other Lyme disease tests are sometimes used:
- PCR (polymerase chain reaction) – Checks for the presence of Lyme bacteria DNA. Only recommended on synovial fluid from inflamed joints. Not useful for routine Lyme testing.
- C6 peptide ELISA – Checks for antibodies to a specific Borrelia antigen. May be more sensitive in later Lyme disease.
- Culture – Tries to grow Borrelia from blood or other infected fluid samples. Low sensitivity and not routinely performed.
- Brain imaging – MRI can sometimes detect brain lesions associated with Lyme neuroborreliosis.
In summary, standard two-tier antibody detection tests using blood samples remain the primary means for diagnosing Lyme disease. Other methods may complement this approach in specific clinical situations.
Lyme disease treatment
If tested within 4-6 weeks of tick bite, and the results are positive, then oral doxycycline antibiotic treatment is typically given even without symptoms present. Treatment courses are generally 2-3 weeks.
If symptoms of Lyme disease like rash or fever are already present, doxycycline or amoxicillin antibiotics are also started immediately for 2-4 weeks. In more severe disseminated Lyme disease, IV antibiotics may be given initially.
Most cases of Lyme disease can be treated successfully with appropriate oral antibiotics. Delaying treatment can increase risk of disease progression and complications. Make sure to take the full antibiotic course as prescribed.
Antibiotics for Lyme disease
The following antibiotics are commonly used to treat different stages of Lyme disease:
| Antibiotic | Route | Dosage | Duration |
|---|---|---|---|
| Doxycycline | Oral | 100 mg twice per day | 14-21 days |
| Amoxicillin | Oral | 500 mg three times per day | 14-21 days |
| Cefuroxime axetil | Oral | 500 mg twice per day | 14-28 days |
| Ceftriaxone | IV | 1-2 g per day | 14-28 days |
For Lyme arthritis, longer courses of oral antibiotics for 1-2 months may be prescribed. IV antibiotics are an option for Lyme neuroborreliosis involving the nervous system.
Lyme disease prevention
You can take these key steps to prevent Lyme disease if you live or spend time in tick-prone areas:
- Avoid wooded and bushy areas with high grass and leaf litter.
- Walk in the center of trails to avoid overgrown vegetation.
- Use EPA approved insect repellents containing DEET, picaridin or lemon eucalyptus oil.
- Treat clothing and gear with products containing 0.5% permethrin.
- Wear long sleeves, long pants and closed toe shoes when outdoors.
- Tuck pants into socks to keep ticks on outside of clothing.
- Perform thorough tick checks after being outdoors.
- Remove ticks promptly using fine-tipped tweezers. Do not crush the tick’s body.
- Take a shower soon after coming indoors. Ticks often still roam for an hour or more before attaching.
- Talk to your vet about tick prevention products for your pets.
- Clear brush and leaf litter in your yard. Move playsets away from woods.
- Consider hiring a pest control specialist to treat your yard with acaricides to reduce ticks.
Being bitten by an infected deer tick is the primary way people get Lyme disease. Be vigilant about checking for ticks after potential exposure. Remove any attached ticks as soon as possible. Monitor for any Lyme symptoms in the weeks following significant tick bites. If concerned, get tested and promptly treated as needed. Taking preventive actions will greatly reduce your chances of contracting Lyme disease.
Conclusion
When to get tested for Lyme disease after a tick bite depends on these key factors:
- If the tick was attached for less than 36 hours, testing is not useful at that time.
- If a tick was embedded for 36 hours or longer, get a Lyme disease test 3-4 weeks after the bite as a precaution.
- If symptoms like rash or fever appear within days to weeks, get tested for Lyme disease right away.
- Lyme testing looks for Lyme bacteria antibodies in the blood. The two-tier test approach is recommended.
- Oral antibiotics like doxycycline are used to treat Lyme disease. IV antibiotics may be needed for disseminated cases.
- Practice tick bite prevention and do thorough tick checks when outdoors to prevent Lyme disease.
In summary, closely monitor for symptoms after any tick bites, and get prompt Lyme disease testing and treatment if concerning symptoms emerge. But routine immediate testing after tick bites is often not necessary if the tick was attached for less than 36 hours or if no symptoms are present. Being vigilant and taking preventive precautions are your best defenses against Lyme disease.