They’re two entirely different illnesses—but they still share a few common signs.
COVID-19 first emerged in the US in February, around the same time that the annual influenza virus was nearing its peak. But while the flu has officially died down, COVID-19 continues to circulate—now, at the same time instances of another illness have historically popped up: Lyme disease.
Even more concerning: While Lyme disease is traditionally difficult to diagnose, the current COVID-19 pandemic may make diagnosing Lyme disease even more complicated than usual, due to similar symptoms shared by Lyme disease and COVID-19. Here’s what you need to know as we head into the summer months, when Lyme disease diagnoses typically increase.
First: What is Lyme disease?
Lyme disease is the most common vector-borne disease—or illness caused by pathogens passed on from one living organism to another—in the US, according to the Centers for Disease Control and Prevention (CDC). Lyme disease is caused by the bacterium Borrelia burgdorferi, and transmitted to humans through the bite of infected blacklegged or deer ticks.
Each year, approximately 30,000 cases of Lyme disease are reported by state health departments and the District of Columbia, per the CDC. However, this is only a fraction of the actual cases. The health organization estimates that up to 300,000 people may get Lyme disease each year in the United States.
It’s important, however, to understand that just coming into contact with a tick doesn’t always lead to a Lyme disease diagnosis. “Generally, a tick has to be in contact with you for 36 hours for it to infect you with Lyme disease,” Purvi Parikh, MD, an immunologist at NYU Langone Health and member of Physicians for Patient Protection, tells Health.
For the sake of this specific article, we’re also mainly focusing on early or acute Lyme disease, the symptoms of which typically show up within three days to a few months after a tick bite, and for which a short course of oral antibiotics is usually curative, according to the National Institute of Allergy and Infectious Diseases (NIAID). But it’s essential to point out that there are other illnesses associated with Lyme disease, like Post-Treatment Lyme Disease Syndrome (PTLDS), in which those previously treated for Lyme disease still experience symptoms even after finishing treatment, per the CDC; and chronic Lyme disease (CLD), used to describe illness in those with Lyme disease, as well as the symptoms in people who have no clinical or diagnostic evidence of a current or past infection with B. burgdorferi, per the NIAID.
What are the symptoms of Lyme disease, and how are they similar to COVID-19?
The CDC breaks up Lyme disease symptoms into early symptoms (within three to 30 days after a tick bite), and late symptoms (within days to months after a tick bite).
Early signs and symptoms of Lyme disease:
- Fever and chills
- Muscle and joint aches
- Swollen lymph nodes
- Erythema migrans (EM) rash
The EM rash is important—per the CDC, it occurs in about 70-80% of all infected people at the site of the tick bite. The rash sometimes has a “bulls-eye” appearance and can feel warm to the touch, but isn’t usually itchy or painful.
Late signs and symptoms of Lyme disease:
- Severe headaches and neck stiffness
- Additional EM rashes on the body
- Facial palsy
- Arthritis with severe joint pain and swelling, often in large joints.
- Intermittent pain in tendons, muscles, joints, and bones.
- Heart palpitations/irregular heartbeat
- Dizziness or shortness of breath
- Inflammation of the brain and spinal cord
- Nerve pain
- Shooting pains, numbness, or tingling in the hands or feet.
If some of those Lyme disease symptoms look familiar, that’s because many overlap with symptoms of COVID-19. The CDC currently lists 11 different symptoms associated with coronavirus—all of which can turn up within two to 14 days after exposure to the virus:
Signs and symptoms of COVID-19:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
What are the differences between Lyme disease and COVID-19?
Despite some of the same symptoms, the similarities between Lyme disease and COVID-19 stop there. The biggest difference, Dr. Parikh says, is the site of entry into the body for both illnesses. “Influenza, cold viruses, and coronavirus enter the body through the nasal passageways and lung tissues, so defining symptoms of these infections are most often respiratory,” she explains. Tick-borne microbes, on the other hand, enter the body through the skin and bloodstream, so symptoms often include rashes and odd systemic symptoms.
That also means protection against both illnesses is different: For Lyme disease, the CDC suggests avoiding exposure to ticks by limiting time spent in grassy, brushy, or wooded areas; wearing long-sleeved shirts and pants; and using insect repellent that also protects against ticks. For COVID-19, the CDC recommends limiting close, person-to-person contact with those outside of your immediate household, wearing face coverings, and washing hands regularly.
Another stand-out difference between Lyme disease and COVID-19 are the testing and treatment options for each. Per the CDC, there’s a two-step process in regards to testing for Lyme disease—both of which are blood tests. Two positive (or equivocal) tests indicates a diagnosis of Lyme disease. Diagnosis of COVID-19, on the other hand, requires a positive PCR (polymerase chain reaction) test that shows you have detectable RNA of the virus. Those tests may be done through nasal or throat swabs, or saliva samples.
It should also be noted that, while those who have underlying conditions like diabetes or are immunocompromised may experience more severe outcomes for COVID-19, Lyme disease doesn’t appear to be one of those conditions, Alexa Meara, MD, a rheumatologist at The Ohio State University Wexner Medical Center, tells Health. “Lyme disease is a bacterial infection that is treated by antibiotics and does not make you immunosuppressed,” she says.
Because it’s a bacterial infection, Lyme disease is usually treated with oral antibiotics like doxycycline or amoxicillin, and patients typically “recover fully and quickly with appropriate treatment,” says Dr. Parikh. That said, the CDC points out that if the initial symptoms of Lyme aren’t caught early enough and spread to the nervous system or heart, intravenous treatment with antibiotics such as ceftriaxone or penicillin may be used. But for COVID-19, which is caused by a virus, there’s currently no approved treatment, and many people are able to recover at home with symptom management. Those with emergency warning signs of severe COVID-19—trouble breathing, persistent pain and pressure in the chest, bluish lips or face—should, however, seek immediate medical attention.
The similarities and differences between COVID-19 and Lyme disease only solidify the fact that, if you’re feeling unwell right now—when both Lyme disease and COVID-19 are circulating in the US—you should check in with your doctor regarding next steps for treatment.