Lyme disease is caused by the bacteria Borrelia burgdorferi and 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 joints, the heart, and the nervous system. Lyme disease treatment is most straightforward when started early but can become more complicated when diagnosis and treatment are delayed.
How is Lyme disease transmitted?
Lyme disease bacteria, Borrelia burgdorferi, live in the guts of blacklegged ticks. The ticks pick up the bacteria when feeding on infected hosts, often small mammals like mice or deer. When the tick later feeds on human blood, the bacteria can be transmitted through the bite. The risk of transmission increases the longer the tick is attached, with transmission uncommon until 36-48 hours of attachment. Removing ticks quickly can prevent infection.
Lyme disease primarily occurs in areas with large populations of blacklegged ticks, especially forests and grassy areas in Northeastern, Mid-Atlantic, and North-Central states. The ticks feed on host animals in the spring and summer and then seek out their final blood meal, often from deer, in the fall. The majority of human Lyme disease cases occur during the summer months when the small nymph-stage ticks are abundant and hard to notice on the skin.
What are the symptoms of early Lyme disease?
Many people with Lyme disease develop an expanding rash at the site of the tick bite called erythema migrans. The rash occurs in 60-80% of infected people and begins as a small red spot that expands over several days into a large circle or oval, often measuring over 15 inches across. The rash is rarely itchy or painful and can have partial central clearing, giving it a “bull’s-eye” appearance.
Along with the rash, early symptoms of Lyme disease include:
- Flu-like symptoms like fever, chills, headache, muscle aches, fatigue
- Swollen lymph nodes
- Joint pain and swelling, often in the knees
Symptoms typically begin 3 to 30 days after a tick bite. When the rash is present, diagnosis is straightforward, but not all rashes at the site of a tick bite are due to Lyme disease. Blood tests can help confirm Lyme but are not always positive early in infection. If a high suspicion for early Lyme remains, antibiotics can be started without waiting for test results.
What are the stages and symptoms of later, untreated Lyme disease?
Early Disseminated Lyme Disease
If initial Lyme infection goes untreated, the bacteria can spread through the bloodstream and cause symptoms throughout the body. This early disseminated stage still occurs weeks to months after the initial tick bite. Symptoms are similar to early Lyme but often more severe and can include:
- Multiple rashes in areas other than the tick bite
- Facial palsy and muscle weakness
- Conjunctivitis and eye inflammation
- Meningitis with severe headache and neck stiffness
- Irregular heart rhythms like atrioventricular block
- Arthritis symptoms spreading to other joints
Late Disseminated Lyme Disease
After months or years of untreated infection, Lyme bacteria can cause chronic inflammatory responses that lead to severe symptoms throughout the body:
- Arthritis eventually affecting most joints
- Neurological symptoms like numbness, tingling, headache, memory issues, mood changes
- Heart palpitations and fainting due to changes in heart rate or rhythm
- Intermittent pain and swelling of the testicles, eyes, liver, or spleen
This late disseminated stage arises when the infection has been active for over a year. The varied symptoms reflect the wide-ranging effects Lyme bacteria can have as inflammation damages different tissues and organ systems.
When should I suspect late Lyme disease?
You should suspect late Lyme disease if you have a history of potential tick exposure and then develop:
- Gradual unexplained onset of multiple symptoms affecting different body systems
- Joint pain or swelling that comes and goes and moves from joint to joint
- Neurological symptoms like cognitive issues, numbness, tingling, nerve pain
- Heart symptoms like lightheadedness, heart palpitations, fainting
You may not remember a tick bite or rash. Consider late Lyme especially if you spend time in wooded areas where Lyme is common and have ongoing symptoms consistent with disseminated infection. Testing is recommended whenever late Lyme is suspected.
How is late Lyme disease diagnosed?
Diagnosing late Lyme disease can be more difficult than early Lyme but uses a combination of:
- Clinical exam – A detailed history and exam looking for characteristic symptoms affecting various body systems
- Blood tests – Specifically the Lyme ELISA and immunoblot to detect antibodies against Lyme bacteria. Tests are most reliable when used in symptomatic patients.
- Other lab tests – Like a complete blood count, metabolic panel, inflammatory markers, and liver tests to assess the severity of any organ involvement
- Imaging – Potentially MRI scanning for joint inflammation or evidence of neurological changes
- Lumbar puncture – To analyze spinal fluid for signs of inflammation or presence of Lyme antibodies or bacteria when symptoms suggest neurological infection
Diagnosis relies heavily on clinical judgement in the setting of supportive blood testing and imaging. Symptoms of late disseminated Lyme can mimic other conditions, so physicians must weigh all evidence carefully.
What antibiotics treat late Lyme disease?
Like early Lyme, oral antibiotics are first-line for treating late Lyme disease. Intravenous antibiotics are an option for more severe symptoms:
Oral antibiotics
- Doxycycline – 100 mg twice daily for 2 to 4 weeks
- Amoxicillin – 500 mg three times daily for 4 to 6 weeks
- Cefuroxime – 500 mg twice daily for 4 to 6 weeks
Intravenous antibiotics
- Ceftriaxone – 2 grams daily for 2 to 4 weeks
- Cefotaxime – 2 grams every 8 hours for 2 to 4 weeks
- Penicillin G – 5 million units every 6 hours for 4 to 6 weeks
IV antibiotics are recommended for:
- Symptoms persisting after a trial of oral antibiotics
- Severe arthritis unresponsive to oral agents
- Signs of neurological infection like meningitis or encephalitis
- Advanced heart block or risk of other cardiac complications
Doctors tailor the antibiotic course based on the patient’s symptoms. IV therapy is often done as an outpatient for 2 to 6 weeks. Oral antibiotics generally follow IV treatment to complete an adequate course.
What is the treatment response with late Lyme disease?
With aggressive antibiotic treatment, late Lyme disease generally responds well. However, some symptoms may take weeks to months to fully resolve.
- Joint inflammation improves within several weeks but mild arthritis may persist
- Fatigue, headache, and cognitive issues often start improving within the first 1-2 weeks
- Heart conduction abnormalities resolve within 1 week with IV antibiotics
- Nerve pain, numbness, and paresthesias may slowly improve over 6 months
Patients are monitored clinically to ensure symptoms continue improving after finishing antibiotics. Additional IV or oral antibiotic courses can be done if needed but usually do not provide added benefit.
For those with prolonged fatigue, cognitive dysfunction, pain, or neuropathy, supportive care is often needed after antibiotics. This includes physical therapy, counseling, treatment of sleep disorders, and potentially medications for nerve pain or headaches.
What are the risks of leaving late Lyme untreated?
Without treatment, late disseminated Lyme can cause permanent damage to the nervous system, joints, heart, and other areas affected by inflammation:
- Chronic arthritis leading to permanent joint destruction and disability
- Heart block requiring a permanent pacemaker
- Neuropathic pain that does not resolve
- Chronic encephalopathy with dementia-like cognitive impairment
- Numbness or weakness from nerve injury
In rare cases, the untreated infection could even be fatal. Studies show patients treated for late Lyme have lower long-term mortality than those who remain undiagnosed and untreated. This highlights the importance of considering late Lyme as a possible cause of unexplained symptoms and utilizing appropriate diagnostic testing and antibiotic treatment when the disease is suspected.
What is post-treatment Lyme disease syndrome?
Up to 20% of patients have ongoing symptoms like fatigue, joint pain, and neurological complaints that persist for 6 months or more after antibiotic treatment. This is called post-treatment Lyme disease syndrome or PTLDS. It likely results from residual inflammatory damage or the body’s dysfunctional immune response rather than persistent infection. Prolonged or repeat antibiotics have not proven beneficial.
Instead, managing PTLDS involves:
- Treating any other medical conditions contributing to symptoms
- Physical therapy and rehab to improve function
- Medications to help relieve join pain, nerve pain, headaches, and insomnia
- Cognitive behavioral therapy and support groups to help cope with chronic symptoms
Most patients with PTLDS do gradually improve with time. However, some never fully return to their pre-infection health and functionality.
Can late Lyme disease be prevented?
The best way to avoid complications of late Lyme disease is prevention:
- Avoid areas with lots of ticks during peak season and walk in the center of trails
- Use EPA approved insect repellants containing DEET on skin and clothes
- Wear pants tucked into socks and long sleeves while in wooded areas
- Check carefully for ticks after being outside and remove any attached ticks
- Consider preventative antibiotics after an identified tick bite in Lyme endemic regions
- Treat any rashes or early Lyme symptoms promptly
Being vigilant about tick precautions, doing frequent tick checks, and seeking early treatment can prevent Lyme disease from progressing to later disseminated stages. A Lyme disease vaccine for humans was approved in 2022 and may provide another prevention option when available.
Conclusion
Late Lyme disease treatment relies on clinical suspicion and recognition of characteristic symptoms along with supportive blood and imaging tests. Oral antibiotics are first-line but intravenous antibiotics are often needed for complicated cases with severe joint, cardiac, or neurological involvement. Most symptoms respond well to 2-4 weeks of antibiotic therapy but some can take much longer to fully resolve. A small percentage of patients have persistent post-treatment symptoms that require symptomatic management. Leaving late Lyme untreated risks permanent inflammatory damage, so prompt diagnosis and antibiotic treatment are key to preventing long-term complications. Ongoing prevention efforts also remain crucial for lowering the risks from this widespread tick-borne disease.