Changes in Smell Can Be a Sign of Lyme Disease

Lyme disease may affect smell, taste, and sensory perception
Some patients report hyperosmia or heightened sensitivity to odors
Neurologic Lyme disease may alter multiple chemosensory pathways

Changes in smell have been described in both COVID-19 and Lyme disease.

According to Parma and colleagues, “A sudden loss of smell [and] taste is consistent with the now typical presentation of COVID-19 symptoms.”²

Patients with Lyme disease have also reported impaired or heightened smell perception, particularly in the setting of neurologic symptoms.^5,6

Lyme Disease and Changes in Smell

An impaired or heightened sense of smell has been described in patients with neurologic disorders, autoimmune diseases, fibromyalgia, and Lyme disease.^3-5

A decreased sense of smell (hyposmia) has been described in patients diagnosed with fibromyalgia.

These patients had “significantly lower thresholds of smell compared to healthy controls,” wrote Amital and colleagues.⁴

Meanwhile, another study found that 50% of 16 patients with Lyme disease suffered from hyperosmia (heightened sense of smell) versus none of the 18 control subjects.⁵

“The high prevalence of this olfactory disorder found in our study suggests the need for further studies of olfactory function in Lyme disease,” concluded the authors.⁵

Neurologic Lyme Disease May Affect Multiple Senses

Fallon and colleagues described hypersensitivity involving photophobia, sound sensitivity, touch, taste, and smell in patients with neurologic Lyme disease.⁶

“Foods may taste abnormally sour and bitter,” Fallon wrote. “Smells may seem overly intense and noxious.”⁶

For a broader overview, visit our Neurologic Lyme Disease hub.

Other Chemosensory Disturbances

Parma and colleagues found that COVID-19 patients may experience broader chemosensory disturbances beyond changes in smell alone.²

The chemosensory system refers to the body’s perception of chemical signals through smell, taste, and chemical sensitivity.

“These results show that COVID-19-associated chemosensory impairment is not limited to smell, but also affects taste and chemesthesis.”²

The authors reported relatively few cases involving distorted smells (parosmia) or phantom smells (phantosmia).²

Additional chemosensory disturbances include:

• Anosmia — loss of the ability to detect smells
• Hyposmia — decreased sensitivity to smells
• Ageusia — loss of taste function
• Hypogeusia — reduced ability to taste
• Parosmia — distorted smell perception
• Dysgeusia — distorted taste perception
• Phantosmia — smelling odors that are not present
• Phantogeusia — phantom metallic or salty taste sensations

Lyme Disease May Be Overlooked

Changes in smell and taste are often associated with viral illnesses, but Lyme disease may also affect sensory processing and neurologic pathways.

Clinicians may need to consider Lyme disease in patients presenting with unexplained smell disturbances, particularly when accompanied by neurologic or multisystem symptoms.

Frequently Asked Questions

Can Lyme disease affect your sense of smell?

Yes. Some patients with Lyme disease report altered smell perception, including hyperosmia and hyposmia.

What is hyperosmia?

Hyperosmia refers to an abnormally heightened sense of smell.

Can Lyme disease cause taste changes?

Yes. Neurologic Lyme disease may affect both taste and smell perception.

What is phantosmia?

Phantosmia refers to smelling odors that are not actually present.

Can COVID-19 and Lyme disease both affect smell?

Yes. Both illnesses have been associated with smell and taste disturbances.

Can smell changes occur in neurologic Lyme disease?

Yes. Patients with neurologic Lyme disease may experience hypersensitivity involving smell, taste, sound, touch, and light.

Clinical Takeaway

Lyme disease may contribute to smell and taste disturbances, particularly in patients with neurologic involvement.

Hyperosmia, hyposmia, altered taste perception, and multisensory hypersensitivity may reflect broader neurologic dysfunction.

Changes in smell should not automatically be attributed to viral illness alone, especially in patients with possible tick exposure or multisystem symptoms.

Related Articles

These related articles explore neurologic Lyme disease, sensory hypersensitivity, tinnitus, and central sensitization.

What’s That Smell?
Study Finds Hearing Loss and Tinnitus Common in Patients With Lyme Disease
Central Sensitization Syndrome Worsens Lyme Disease Symptoms
Autonomic Dysfunction and Lyme Disease
Lyme Disease Symptoms Guide

References

1. Sutherland S. Mysteries of COVID Smell Loss Finally Yield Some Answers. Scientific American. November 18, 2020.
2. Parma V, Ohla K, Veldhuizen MG, et al. More Than Smell—COVID-19 Is Associated With Severe Impairment of Smell, Taste, and Chemesthesis. Chem Senses. 2020;45(7):609-622.
3. Perricone C, Shoenfeld N, Agmon-Levin N, et al. Smell and autoimmunity: a comprehensive review. Clin Rev Allergy Immunol. 2013;45(1):87-96.
4. Amital H, Szekanecz Z, Szucs G, et al. Olfactory impairment in patients with the fibromyalgia syndrome and systemic sclerosis. Immunol Res. 2014;60(2-3):201-207.
5. Puri BK, Champion B, Green R, et al. Hyperosmia in Lyme disease. Arq Neuropsiquiatr. 2014;72(8):614-615.
6. Fallon BA, Nields JA. The neuropsychiatric manifestations of Lyme borreliosis. Psychiatr Q. 1992;63(1):95-117.

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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