Atypical Symptoms: A Rising Trend in Lyme Disease
It's concerning when a disease presents in ways we don't expect. This is especially true when it comes to Lyme disease, a condition that's becoming increasingly prevalent. Let's dive into a real-life case that highlights how Lyme disease can sometimes be a tricky diagnosis.
Our story begins with a 53-year-old woman who walked into the hospital with a persistent fever. This wasn't just a low-grade temperature; it was fluctuating between 100° and 102°F and accompanied by chills and muscle aches (myalgias). These fevers occurred almost daily, initially at night but later in the mornings too. She found some relief with ibuprofen and acetaminophen. About a week into this, she developed a red, non-itchy rash that started on her chest and back, eventually spreading to her arms and legs. She also reported joint pain in her shoulders, elbows, knees, and hips, along with muscle aches in her upper arms. The patient had a history of atrial fibrillation, hypertension, hyperlipidemia, and asthma.
On the morning of her hospital visit, her joint pain had intensified, coming and going with stiffness. The pain didn't respond to ibuprofen, and a fever of 104°F had prompted her to seek immediate medical attention.
Further investigation revealed nausea, decreased appetite, slight weight loss, headaches, a mild cough, and a sore throat that cleared up quickly. She denied any recent travel, insect bites, or drug use. She had a dog and had fed a budgie bird but had no other significant animal exposure. She had visited a drive-through safari park several times in the previous months with the car windows typically closed.
During the physical examination, doctors noted mild tenderness in her elbows, knees, and hips without swelling or warmth. There were also blanching erythematous patches on her chest, trunk, back, upper arms, and legs. Laboratory tests showed an elevated white blood cell count and inflammatory markers, with a CRP of 4.3 mg/dL and an ESR of 63 mm/hr. Her kidney and liver function tests were normal, as were complement levels. M protein was positive for IgM lambda. Ferritin was mildly elevated at 267 ng/mL, and ANA was 1:320. Other autoimmune serologies were negative. Imaging tests of her chest, abdomen, and pelvis were also unremarkable.
So, what was going on with this patient?
From a rheumatologic perspective, doctors initially considered an acute viral illness, such as parvovirus B19, due to the fever, anemia, and joint pain. However, given the rash, fever, and positive M protein, they also considered Schnitzler syndrome, although that is typically associated with neutrophilic urticaria, and the M protein is IgM kappa.
Because her liver function was normal and ferritin only mildly elevated, adult-onset Still's disease was deemed unlikely. Although a clear infection hadn't been found, antibiotics were initiated by the Infectious Disease team, and her fever resolved, suggesting a bacterial infectious etiology. Anaplasma and babesia PCR testing was negative, as was Rocky Mountain spotted fever IgG. However, Lyme Western blot tests for both IgG and IgM came back positive.
With antibiotic therapy, her joint pain and rash improved, which supported a diagnosis of Lyme disease. She was treated with a four-week course of doxycycline. The patient's joint pain and fevers resolved with antibiotics, making Lyme disease the most likely diagnosis.
But here's where it gets controversial...
This case highlights an unusual presentation of Lyme disease. Typically, fever in Lyme disease is low-grade and occurs in the early stages, often alongside erythema migrans (the classic bullseye rash) or as part of a viral-like syndrome. High or spiking fevers are not typical and should prompt consideration of alternative diagnoses or coinfections with other tick-borne pathogens, such as anaplasma or babesia. In this case, these were ruled out.
And this is the part most people miss...The rash in Lyme disease is usually erythema migrans, which begins as a single expanding lesion at the tick bite site. In early disseminated Lyme disease, multiple erythema migrans lesions may develop at distant sites, but a true diffuse, non-annular rash is not typical. This patient's generalized rash and high fevers were atypical for Lyme disease.
The Takeaway
This case underscores the importance of considering a broad range of potential diagnoses and being aware of the potential for atypical presentations, especially in areas where Lyme disease is common. The disease doesn't always follow the textbook.
Lyme disease cases are on the rise, with a significant increase in recent years. In 2023, Ohio reported 1,301 confirmed cases, more than double the 554 cases reported in 2022. Lyme disease vigilance in the region will continue to be important.
What are your thoughts? Do you think doctors are prepared for the increasing complexity of Lyme disease presentations? Share your opinions in the comments below!
