Can Lyme Disease Cause Changes in Smell or Taste?

Changes in smell and taste can occur in Lyme disease.
Symptoms may include loss of smell, heightened smell, or altered taste.
COVID-19 is one possible cause, but it is not the only explanation.

Changes in smell and taste can occur in Lyme disease, although they are less common than fatigue, joint pain, or neurological symptoms. Disturbances of smell—including loss of smell (anosmia), reduced smell (hyposmia), heightened smell (hyperosmia), and distorted smell (parosmia)—have also been reported in Lyme disease and other neurological disorders.

Patients with Lyme disease frequently report changes in smell or taste. Similar symptoms have also been described in patients with Alzheimer’s disease, Parkinson’s disease, autoimmune disorders, and fibromyalgia.

These symptoms may occur alone but are more often reported alongside other neurological manifestations of Lyme disease.

Patients describe smell and taste changes in different ways. Some notice a loss of smell, while others report heightened sensitivity to odors, distorted smells, metallic taste, bitter taste, salty taste, or that familiar foods suddenly taste unusual. These symptoms have many possible causes and should be evaluated in the context of the patient’s overall medical history.

Can Lyme disease increase sensitivity to smells?

One small controlled study specifically examined hyperosmia (heightened sensitivity to odors) in Lyme disease. Puri and colleagues administered a questionnaire regarding smell sensitivity to 16 serologically positive Lyme disease patients and 18 healthy controls.

Hyperosmia was reported by 8 of the 16 Lyme disease patients (50%) compared with none of the control subjects (0%) (p=0.0007). Although this was a relatively small study, it remains the only published controlled study specifically evaluating hyperosmia in Lyme disease.

“The high prevalence of this olfactory disorder found in our study suggests the need for further studies of olfactory function in Lyme disease,” the investigators concluded.

Because of the study’s limited size, these findings should be interpreted cautiously until confirmed in larger studies.

Fallon and colleagues described sensory hypersensitivity in patients with Lyme disease, including photophobia, sound sensitivity, touch sensitivity, and altered taste and smell. They noted that foods may taste unusually sour or bitter, while odors may seem unusually intense or unpleasant.

Why might Lyme disease affect smell or taste?

The exact mechanism remains uncertain. Proposed explanations include inflammation involving the nervous system, cranial nerve dysfunction, central nervous system involvement, autonomic dysfunction, altered sensory processing, or central sensitization. Additional research is needed before any single mechanism can be confirmed.

How does this compare with COVID-19?

COVID-19 brought widespread attention to smell and taste disorders. According to Parma and colleagues, sudden loss of smell and taste became one of the characteristic symptoms of COVID-19 infection.

Most patients recover their sense of smell, although recovery can take weeks or months and some develop persistent smell distortion.

The investigators also found that COVID-19-related chemosensory dysfunction often involved more than smell alone. Taste and chemesthesis—the ability to sense chemical irritation such as the burn from chili peppers or the cooling sensation of menthol—were frequently affected as well.

Most COVID-19 patients in their study did not report qualitative smell disturbances such as parosmia (distorted smells) or phantosmia (phantom smells), although these symptoms were observed in a minority of cases.

Can Lyme disease cause a metallic taste?

Some patients with Lyme disease report altered taste (dysgeusia), including metallic, bitter, salty, or otherwise distorted tastes. Taste disturbances may result from neurologic involvement, medications, or other medical conditions. Because smell contributes substantially to flavor perception, patients who believe they have lost their sense of taste may actually have an underlying smell disorder.

Common smell and taste disturbances

Frequently Asked Questions

Can Lyme disease cause loss of smell?

Yes. Although not well studied, disturbances in smell—including loss of smell, reduced smell, and heightened smell—have been reported in Lyme disease. Additional research is needed to determine how frequently these symptoms occur.

Can Lyme disease cause a metallic taste?

Some patients report metallic or distorted taste. Because smell contributes heavily to flavor perception, an underlying smell disorder may also contribute to these symptoms.

How is Lyme disease different from COVID-19 when smell changes occur?

Loss of smell became a hallmark symptom of COVID-19, but smell disturbances can occur with many neurological and infectious illnesses, including Lyme disease. The patient’s overall symptoms, examination, and medical history help determine the underlying cause.

Clinical Takeaway

Changes in smell or taste are not unique to COVID-19. Although the published evidence is limited, Lyme disease has also been associated with hyperosmia and other chemosensory disturbances. Persistent or unexplained changes in smell or taste—particularly when accompanied by fatigue, neurological symptoms, joint pain, or a history of tick exposure—should prompt a comprehensive medical evaluation.

Smell and taste disturbances may occur in Lyme disease, but they should always be evaluated in the broader clinical context because many neurological, infectious, autoimmune, and ear, nose, and throat disorders can produce similar symptoms.

Related Articles

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Autonomic dysfunction in Lyme disease
Study finds hearing loss and tinnitus common in patients with Lyme disease
Central sensitization syndrome worsens Lyme disease symptoms?

Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention