Lyme Disease and Mold Exposure

Overlap of symptoms can make diagnosis difficult

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There is much more to chronic Lyme disease than the disease itself. A Lyme disease infection can make you more susceptible to common environmental toxins, such as mold, while mold-related illnesses may worsen your Lyme disease symptoms.

It is a hand-in-hand relationship that we don't yet fully understand. Moreover, the very diagnosis of "chronic" Lyme disease remains the subject of intense debate with little understanding as to why some people remain ill for months and even years after an infection has cleared.

What has become increasingly apparent is that, in cases of chronic illness, we have to consider whether co-existing conditions may be contributing to—or even driving—the illness. Mold is one such factor that research scientists are exploring.

Understanding Lyme Disease

Lyme disease is caused by a bacteria, Borrelia burgdorferi, which is passed to humans through a bite from an infected black-legged or deer tick. Acute symptoms can develop anywhere from three to 30 days after the bite and include fever, chills, headache, fatigue, swollen lymph nodes, and muscle and joint pain.

A uniform, round hive will usually develop at the site of the tick bite. In around a third of cases, the rash will develop a characteristic "bullseye" appearance with a round, red, circular border and a lighter interior.

As the infection progresses, symptoms of Lyme disease can include:

  • Severe headache
  • Neck stiffness
  • Rashes on other parts of the body
  • Severe arthritic pain, particularly in the knees
  • Drooping on one or both sides of the face
  • Irregular heartbeat
  • Fatigue
  • Inflammation of the brain (encephalitis)
  • Inflammation of the lining of the brain or spinal cord (meningitis)
  • Shooting, numbness, or tingling in the hands or feet (peripheral neuropathy)

Infection is typically treated with an antibiotic, such as doxycycline, for anywhere from one to four weeks.

Post-Treatment Lyme Disease Syndrome

Once resolved, around five percent of people will develop persistent symptoms which some refer to as "chronic" Lyme disease. It's contentious diagnosis, often little supported.

While the Centers for Disease Control and Prevention (CDC) acknowledges that certain symptoms can persist after treatment is completed (such as joint pain and neuropathy), they will almost universally resolve within six months or less.

Beyond that time, there is no clinical evidence that the persistent symptoms—most specifically chronic fatigue—are in any way linked to Lyme disease. For these individuals, the CDC has classified the illness as post-treatment Lyme disease syndrome (PTLDS).

Mold and Lyme Disease

In recent years, there have been anecdotal reports of a connection between mold and PTLDS. It has mostly been related to research on the incidence of mold toxin exposure in people with chronic fatigue syndrome (CFS).

A recent study from California State University Northridge and Texas Tech University Health Science Center reported that 30 percent of people with CFS had evidence of mold toxins in their blood, while 90 percent had likely exposure to mold in water-damaged home or buildings.

While hardly conclusive, the study did highlight the pathway by which fatigue symptoms can develop, many of which Lyme disease experts believe contribute to PTLDS.

Understanding Mold

Molds are a type of fungi which produce airborne spores. As with other types of fungi (such as yeast), molds produce toxic chemicals, called mycotoxins, which they use to stake out territory on a host and weaken the immune defenses in order to proliferate.

Ongoing mold exposure can become a serious problem, particularly in people with an underlying health condition. We see this commonly in people with advanced HIV infection.

Some researchers have begun to postulate that the same effect may be experienced, to a lesser degree, in people with PTLDS. They argue that exposure to B. burgdorferi increases a person's sensitivity to mycotoxins while exacerbating symptoms of the disease itself.

Even if the primary infection is cleared, the diminished immune response, combined with continued mold exposure, may create the spectrum of symptoms we refer to as PTLDS.

Symptoms of Mold Exposure

Symptoms of mycotoxin exposure can range in severity from mild to life-threatening. In persons with a history of Lyme disease, many of the symptoms can overlap and include:

  • Swollen lymph glands
  • Fatigue
  • Dizziness
  • Muscle weakness
  • Joint and/or muscle pain
  • Irregular heartbeat
  • Anxiety and depression
  • Respiratory symptoms, including asthma and sinusitis
  • Cognitive impairment and "brain fog"
  • Vision problems
  • Ringing in the ears
  • Skin irritation, including psoriasis
  • Sleep problems
  • Low libido

The nonspecific nature these symptoms can make it difficult to pin the cause on one illness or another. To differentiate, doctors will sometimes presumptively test a person with PTLDS for evidence of mold exposure.

Diagnosis and Treatment

Diagnosis of mycotoxic exposure involves a blood test as well as environmental tools to evaluate your living and workspaces. This is especially true if you reside in a water-damaged building where the likelihood of mold is high.

If the results are positive, treatment would involve three steps:

  • Removing mold from your daily environment
  • Taking binding agents to help clear the fungi from your digestive tract
  • Taking antifungal drugs to clear fungus from other parts of your body

Binding agents may include the anti-cholesterol medication, cholestyramine, taken 30 minutes before a meal. To promote detoxification, efforts would be made to avoid constipation.

Amphotericin B is usually the antifungal of choice in treating systemic fungal infections. Because mycotoxin-producing molds generally colonize in the sinuses, gut, bladder, and vagina, treatment may involve both a nasal spray and oral medications. The duration of treatment is largely dependant on the severity of the infection and the types of symptoms involved.

A Word From Verywell

It would be wrong to assume that PTLDS is "all in one's head." While there may be a psychological component that makes certain symptoms worse, every effort should be made to explore co-existing or entirely separate causes of the illness.

Mold exposure may be one such option, but it is not the only one. The simple fact is that, if a person goes through a traumatic experience with Lyme disease, he or she will often be focused on Lyme disease as the sole source of any ongoing illness. And, quite honestly, it's not always the case.

Work with your physician, try to be patient, and ask for a referral to an infectious disease specialist if you believe you may be exposed to mold in your daily environment.


Brewer, J.; Thrasher, J.; and Hooper, D. "Chronic Illness Associated with Mold and Mycotoxins: Is Naso-Sinus Fungal Biofilm the Culprit?" Toxins. 2014; 6(1):66-80. DOI: 10.3390/toxins6010066

Brewer, J.; Thrasher, J.; Straus, D. et al. "Detection of Mycotoxins in Patients with Chronic Fatigue Syndrome." Toxins. 2013; 5(4): 605-17. DOI 10.3390/toxins5040605.

World Health Organization. "Mycotoxins." Geneva, Switzerland; issued October 2011.