For most patients who contract Lyme disease, oral antibiotics will successfully treat the symptoms. However, some patients who get the infection caused by the bacterium Borrelia burgdorferi report lingering symptoms such as fatigue, pain, and joint and muscle aches long after the antibiotics are finished. Sometimes referred to as “chronic” Lyme disease (CLD), the Centers for Disease Control and Prevention (CDC) refers to the condition as post-treatment Lyme Disease symptoms (PTLDS) or post-Lyme disease syndrome (PLDS).

The cause for PTLDS is not only unknown but the term “chronic” Lyme disease is mired in controversy. The National Institute of Allergy and Infectious Diseases reports that CLD “has been used to describe people with different illnesses. While the term is sometimes used to describe illness in patients with Lyme disease, it has also been used to describe symptoms in people who have no clinical or diagnostic evidence of a current or past infection with B. burgdorferi.”

A 2015 report published in the Infectious Disease Clinics of North America points out that “chronic” Lyme disease “has no clinical definition and is not characterized by any objective clinical findings.” In 7 studies conducted in areas where Lyme disease is common, 50% to 88% of 1902 patients referred for suspected infection had no evidence of ever having contracted the disease.

“Most of these patients had either alternative medical diagnoses or had medically unexplained symptoms, such as chronic fatigue syndrome or fibromyalgia,” the study said. “Lyme disease was in many cases diagnosed simply for lack of an alternative diagnosis—referred to in 1 paper as a ‘diagnosis of Lyme disease by exclusion’.”

If it is possible that over half of patients suspected of PTLDS were never exposed, then the question begs how do doctors evaluate patients who report symptoms of the disease? Quest Diagnostics Medical Director of Infectious Diseases, Robert S. Jones, DO, MS, FACP FIDSA helps answer that question. He offered the following recommendations for doctors treating PTLDS patients.

Start from scratch

Robert S Jones, DO MS FACP FIDSA | Quest Diagnostics | Medical Director, Infectious Diseases

“PTLDS can be a frustrating disease,” said Dr Jones. “The first thing I do is make sure I keep an open mind when patients come to me.”

He mentioned the many factors that need to be considered when evaluating patients. These include the patient’s health history, length of symptoms, type of symptoms, where they suspect they contracted Lyme disease, and the possibility of other tick-borne illnesses.

Patient history

Symptoms of Lyme disease may vary depending on the length of time the patient has been infected. While one of the most commonly known symptoms is a rash, Dr Jones recommends physicians consider the patient’s health history.

A 2010 Clinics in Laboratory Medicine article went in depth about the possibility that symptoms may be related to other conditions and reiterated the need to examine all possibilities. “The diagnosis of Lyme disease, especially in the absence of the characteristic rash, may be difficult, since the other clinical manifestations of Lyme disease are not specific. Even the diagnosis of erythema migrans sometimes may be difficult, since the rash initially may be confused with nummular eczema, granuloma annulare, an insect bite, ringworm, or cellulitis.”

Symptoms associated with PTLDS can be even more difficult to attribute. In the Lantos article referenced earlier, more than half of the patients who lacked evidence of Lyme disease “had alternative medical diagnoses or medically unexplained symptoms, such as chronic fatigue or fibromyalgia.“

Length of symptoms

Another critical factor when diagnosing PTLDS is to examine the length of time a patient has been experiencing symptoms. The medical community is well aware that some patients experience prolonged symptoms while being treated for Lyme disease. These symptoms can lead to a “subset of significant functional impairment” including joint and muscle pain, headache, fatigue, neck and backache, irritability, and difficulty with memory and concentration.

The International Lyme and Associated Diseases Society recommends the following timeline in their proposed definition of post-Lyme disease syndromes:

Onset of any of the following subjective symptoms within 6 months of the diagnosis of Lyme disease and persistence of continuous or relapsing symptoms for at least a 6-month period after completion of antibiotic therapy:

  • Fatigue
  • Widespread musculoskeletal pain
  • Complaints of cognitive difficulties

They add that the symptoms must be severe enough to have a significant impact on a patient’s job, education, social, and personal activities.
Location of suspected exposure

Where a person lives and travels is another consideration when diagnosing PTLDS. While Lyme disease is a recognized public health concern, most cases occur in the northeast, mid-Atlantic, and the north-central United States.

“It is important to remember there are different species of ticks across the United States,” Dr Jones explained. Deer ticks, or black-legged ticks, are found across the eastern United States and are the ones that may transmit the bacteria that cause Lyme disease.

(Centers for Disease Control and Prevention)

Other tick-borne illnesses

As Dr Jones pointed out, the location of the suspected infection matters. That information can help doctors eliminate or consider other tick-borne illnesses.

“Different ticks carry different diseases,” Jones said. “Sometimes a single tick can carry more than one disease.”

The CDC reports that Lyme disease is the most commonly reported tick-borne illness. Others include babesiosis, ehrlichiosis, Rocky Mountain spotted fever, anaplasmosis, Southern tick-associated rash illness, Tick-borne relapsing fever, and tularemia.

Taking the next step

PTLDS or “chronic” Lyme disease diagnosis involves a lengthy process of elimination. Besides understanding a patient’s history, one of the first steps to reach a diagnosis and start treatment is to get the right testing done. For more information on how to get started, click here.