by Allison Sayre, MSN, WHNP-BC
Lyme disease, or Lyme borreliosis, is the most common vector-borne illness in North America, with the Centers for Disease Control and Prevention (CDC) estimating approximately 476,000 diagnoses each year in the United States.[1] While public awareness of Lyme disease has grown, its complex symptomatology and potential for delayed onset still make it a clinical enigma, particularly in adults. This can be particularly frustrating for practitioners, as symptom presentation can be vague, episodic, or easily mistaken for other illnesses.
In this article, we will explore the core symptoms of Lyme disease, the unique ways it manifests in adults as compared to children, and the diagnostic challenges that often delay effective treatment.
The Classic Stages of Lyme Disease
Lyme disease in the United States is primarily caused by the spirochete Borrelia burgdorferi, with a few cases borne of other closely related Borrelia species.[2] It is transmitted to humans through the bite of infected deer ticks, also known as “black-legged” ticks (Ixodes scapularis or Ixodes pacificus), primarily located in the eastern and central United States. Nymphal ixodid ticks are most active and abundant in the late spring and early summer, and because most outdoor activity occurs during warmer weather, Lyme disease diagnoses tend to peak during the summer months.[2]
Lyme disease typically progresses in three stages, though not all are aware of (or symptomatic during) every stage:
1. Early Localized Stage (3–30 days post-bite)
The hallmark symptom of Lyme disease is erythema migrans (EM), a bull’s eye rash, or visible red ring around the bite, that appears in 70–80% of cases. However, not all patients develop or notice the rash, making early detection difficult. The rash may be accompanied by flu-like symptoms, including fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes.[1]
2. Early Disseminated Stage (weeks to months post-bite)
In the disseminated stage, the infection may spread through the bloodstream to joints, the nervous system, and the heart. Symptoms can include multiple EM rashes on other parts of the body, migratory arthritis and joint pain, and irregular heartbeat or palpitations (known as Lyme carditis).[1] Lyme Neuroborreliosis (LNB), an infection of the nervous system, is another unfortunate manifestation occurring in approximately 12.5% of Lyme disease patients in the US. Symptoms encompass facial palsy, meningitis, and radiculoneuropathy (degeneration of the spinal cord and peripheral nerves). LNB can also lead to cognitive problems, sleep disturbances, or peripheral neuropathy (numbness, pain, and tingling in the extremities), among other neurological issues. Lyme disease symptoms like these are much slower to manifest after the initial tick bite, and are associated with many other pathologies, making them much harder to diagnose.
Interestingly, while the mechanism of dissemination is still somewhat unclear, the location of the tick bite does not appear to correlate with whether or not the borreliosis infection will become LNB. The current hypothesis is that spirochetes travel through the circulation to the vasa nervorum (peripheral nerve blood supply), where immune amplification and localized inflammation result in damage to peripheral nerve bundles.[3]
3. Late Disseminated/Chronic Stage (months to years post-bite)
This stage is particularly prone to misdiagnosis or underdiagnosis. It has been estimated that up to 20% of Lyme disease cases in endemic areas involve patients who present with prolonged nonspecific symptoms, but lack hallmark features such as EM, LNB, or carditis. [4] In the northeastern US, chronic Lyme arthritis, especially of the knees, is the most common late manifestation of the disease. It can develop as early as two months or as late as two years after infection, occurring in approximately 60% of untreated individuals.[2]
Adult vs. Pediatric Presentation: What’s the Difference?
Though the same pathogen causes Lyme in both adults and children, the presentation can vary significantly. Children are more likely to present with EM, as well as fever and chills, within the first days of infection, which can make early diagnosis easier in pediatric cases.[2,5] However, their EM sites are most often located on the head and neck, while adults are more likely to exhibit EM on legs or abdomen, making the rash in children more difficult to identify and diagnose early.
Additionally, children may be more likely to develop early-disseminated LNB than adults, with cranial nerve palsies and lymphocytic meningitis being the most common manifestations in pediatric cases.[5] Facial palsies caused by Lyme disease often resemble Bell’s palsy; however, it is interesting to note that bilateral facial nerve palsy is a distinctive feature that is almost exclusively associated with Lyme disease.[5] Lyme meningitis is generally difficult to diagnose in both adults and children, as symptoms such as headaches, neck pain, and fever are fairly nonspecific. Differentiation between viral meningitis and Lyme meningitis can be especially difficult in children, as patients experience similar rates of headaches, neck pain, and malaise in both conditions.[4]
Late-stage Lyme disease tends to present similarly in children and adults, and is typically arthritic in nature, most commonly expressed as swelling and pain at the knee joints.[2,5] In contrast, Lyme carditis is predominantly an adult manifestation, affecting 1-8% of adult Lyme patients, and is rarely seen in children.[5]
Why is Lyme So Hard to Diagnose?
1. Lack of Early Symptoms
Unfortunately, many do not recall a tick bite, and according to the CDC, about 30% of patients with Lyme never see or develop the telltale EM rash. Additionally, early flu-like symptoms are easy to dismiss as a passing virus, potentially leading to Lyme disease being left off the list of differential diagnoses.
2. Latency Period
Symptoms can emerge weeks, months, or years after the initial infection. This delayed onset disconnects the infection from its source, leading physicians to focus on more immediate causes for a patient’s symptoms or concerns.
3. Nonspecific Symptoms
Fatigue, joint pain, memory issues, and muscle aches are common to many conditions. Lyme disease does not have a unique symptom profile in later stages, which further hinders clinical recognition and proper diagnosis.
4. Laboratory Testing Limitations
Lyme disease is typically diagnosed through a two-tiered blood test (ELISA followed by Western blot), but these tests detect antibodies and are not specific to spirochetes. The immunoglobulin M (IgM) can be detected 2-4 weeks after EM onset, and immunoglobulin G (IgG) antibodies appear 4-6 weeks after EM. Both IgM and IgG peak at 6-8 weeks and then decline to very low levels for several months. Because the target antibodies may not be present in early infection, or can persist after the infection has resolved, the probabilities of early false negatives or late false positives are relatively high.[4]
The Future of Lyme Disease: Awareness and Advocacy
Lyme disease poses a growing public health concern, particularly as a changing climate may extend the season of transmission. For adults, especially those in high-risk regions or with active lifestyles, self-advocacy is crucial. Understanding the symptoms, seeking prompt medical evaluation after suspected tick exposure, and being informed about the nuances of testing can lead to earlier diagnosis and improved outcomes.
For practitioners, Lyme disease should be a consideration in any adult living in an endemic area and presenting with unexplained multisystem symptoms. While serological testing can be a helpful tool, Lyme is often a clinical diagnosis, particularly in the early or late stages, where laboratory confirmation may be equivocal. That is why it is essential for practitioners to recognize the signs and symptoms of Lyme disease to ensure timely diagnosis and treatment, potentially preventing serious long-term complications.
For researchers, the goal remains to improve early detection methods and develop more accurate diagnostic tools. While clinical trials of new vaccines for Lyme disease are currently underway, there is no reliable vaccine available at present.[1] With continued research and education, the medical community can reduce misdiagnoses and ensure that patients receive the care they need before symptoms become chronic.
Disclaimer:
The information provided is for educational purposes only. Consult your physician or healthcare practitioner if you have specific questions before instituting any changes in your daily lifestyle including changes in diet, exercise, and supplement use.
Allison Sayre, MSN, WHNP specializes in women's health and functional medicine, blending both traditional and integrative approaches. With over 17 years of experience, she has empowered women to reclaim their health through personalized nutrition and supplementation, hormone balancing, and lifestyle modifications. She received her Bachelor of Science from Mount Carmel College of Nursing and her Master of Science from the University of Cincinnati. She has been a certified women’s health nurse practitioner since 2014 and has continued her education and training in functional medicine from both the Institute for Functional Medicine as well as the American Academy of Anti-Aging Medicine.