Lyme disease is caused by a bacterial infection transmitted by ticks. The first sign of infection is usually a rash that appears around or near the site of the tick bite. This rash, called erythema migrans (EM), occurs in approximately 70-80% of infected people and begins to appear anywhere from 3 to 30 days after the bite. So can you tell right away if you have Lyme disease? Here is a closer look at the early signs and timeline of Lyme disease.
The Erythema Migrans Rash
The EM rash is considered the classic initial symptom of Lyme disease. It starts as a small red bump or patch that slowly expands over the course of several days or weeks, forming a circular or oval-shaped rash. The center of the rash often clears as it enlarges, resulting in a bull’s-eye appearance. In some cases, the rash may be uniform in color rather than having a bull’s-eye lesion.
The EM rash usually measures at least 2 inches (5 cm) in diameter. Its size can range from that of a penny to covering a large portion of the arm, leg, or trunk where the tick bite occurred. The rash is not itchy or painful for most people. It typically appears an average of 7 to 14 days after an infected tick bite, but can occur anywhere from 3 to 30 days later.
Key Facts About the EM Rash:
- Appears in 70-80% of Lyme disease cases
- Begins as a small bump or red patch at the site of the bite
- Slowly expands into a large, circular or oval-shaped rash over days or weeks
- Often has a bull’s-eye appearance, with central clearing
- Measurers at least 2 inches (5 cm) in diameter
- Is not itchy or painful in most cases
- Emerges around 3 to 30 days after the tick bite (average is 7-14 days)
Other Early Symptoms
In addition to the rash, some other early symptoms may begin to develop in the first several weeks after infection. These can include:
- Fever
- Chills
- Fatigue
- Body aches
- Headache
- Stiff neck
- Swollen lymph nodes
However, only the EM rash is considered a definitive initial indicator of Lyme disease. The other symptoms are vague and can be caused by many different conditions. Fatigue and headache, for example, are very common complaints with many underlying causes.
Timeline of Symptoms
Lyme disease symptoms typically emerge in the sequence listed below, although the timing can vary:
| Stage | Time After Tick Bite | Symptoms |
|---|---|---|
| Early localized | 3 to 30 days (avg. 7-14 days) | EM rash, fever, chills, headache, fatigue, muscle aches |
| Early disseminated | Weeks to months | Facial palsy, meningitis, heart palpitations, severe headaches, neck stiffness, additional EM rashes |
| Late disseminated | Months to years | Arthritis, central nervous system problems, numbness, tingling in arms/legs |
As shown in the timeline, the hallmark EM rash tends to appear first, in the early localized stage. Other flu-like symptoms may also emerge during this initial period 3 to 30 days after infection. If untreated, later disseminated symptoms involving the nervous system, heart, and joints can emerge weeks, months, or even years later in the advanced stages.
When to See a Doctor
If you develop an EM rash or suspect you’ve been bitten by a tick and have any symptoms of Lyme, it’s important to see a doctor right away. Blood tests and a physical exam can help confirm if Lyme bacteria are present. Early diagnosis and antibiotic treatment are crucial for preventing complications.
You should seek medical attention if you:
- Develop an EM rash
- Experience a spreading skin lesion after a tick bite
- Were bitten by a tick and have fever, chills, headaches, and other flu-like symptoms
- Have facial drooping or numbness, severe headaches, neck pain, dizziness, double vision, chest pain, shortness of breath, an irregular heart beat, or loss of muscle tone
Without treatment, Lyme disease can progress and lead to lasting damage to the heart, joints, and nervous system. So don’t wait if you have suspicious symptoms after a tick bite. See a healthcare provider as soon as possible for proper diagnosis and treatment. Catching it early makes Lyme much easier to cure.
How Lyme Disease is Diagnosed
Doctors use the following approaches to diagnose Lyme disease:
Physical Exam
A physician will perform a complete physical exam and ask about your medical history and any recent tick exposure. They will look for signs of the EM rash and other markers of Lyme, such as facial drooping if neurological symptoms are present.
Blood Tests
Several different blood tests can detect antibodies your body produces in response to the Lyme bacteria:
- Enzyme-linked immunosorbent assay (ELISA): The ELISA test can determine if antibodies against Lyme are present in the blood. However, it has a high rate of false positives, so a positive ELISA result is usually followed up with a Western blot.
- Western blot: The Western blot is currently the standard for confirming Lyme diagnosis after a positive ELISA. It separates and identifies different antibodies and is more specific.
- Polymerase chain reaction (PCR): The PCR test can detect small amounts of the Lyme bacteria’s genetic material in the blood. It is not as widely available as antibody tests.
Blood tests have limitations, especially in the early stages of Lyme when antibody levels are still low. They are better at confirming late infections. A negative result does not completely rule out Lyme disease.
Spinal Tap
If neurological symptoms are present, a spinal tap may be performed to look for antibodies or genetic material from the Lyme bacteria in the cerebrospinal fluid.
Treatment for Lyme Disease
The standard treatment for Lyme disease is antibiotic medications such as doxycycline, amoxicillin, or cefuroxime. The length of treatment depends on how long the infection has been present:
- Early localized Lyme: 14-21 days of antibiotics
- Early disseminated Lyme: 4-6 weeks of antibiotics
- Late disseminated Lyme: 4-6 weeks or longer of antibiotics
Most people respond well to antibiotic treatment, especially when treated in the early stages of Lyme disease. However, a small percentage continue to have symptoms like fatigue and joint pain after treatment, a condition called post-treatment Lyme disease syndrome.
Preventing Tick Bites and Lyme Disease
You can lower your risk of Lyme disease by taking these tick bite precautions:
- Wear long pants and sleeves when in wooded or grassy areas
- Use insect repellent with DEET on exposed skin
- Do tick checks after being outdoors
- Shower soon after coming inside
- Call a doctor if you are bitten by a tick to get it tested for Lyme
- Remove ticks properly with tweezers and disinfect the bite site
Check your body carefully for ticks after spending time in tick habitats like grassy, wooded, and bushy areas. Also check your clothing. Promptly remove any attached ticks you find by grasping them close to the skin with tweezers and pulling straight up. Contact a doctor if any rash, fever, or other symptoms develop after a tick bite.
Conclusion
In summary, the hallmark and earliest sign of Lyme disease is usually the EM rash at the site of the tick bite. This expanding rash appears in the majority of those infected approximately 7 to 14 days after the bite, but can emerge anywhere from 3 to 30 days later. Flu-like symptoms may also be present. While the EM rash is considered diagnostic of Lyme, blood tests can provide confirmation by detecting Lyme antibodies. However, tests have limitations in the early stages. If you suspect Lyme disease after a tick exposure, see a doctor right away for proper diagnosis and prompt antibiotic treatment to prevent complications.