Lyme Disease

Lyme disease is a bacterial infection spread through the bite of infected blacklegged ticks. While most cases can be successfully treated with antibiotics, early recognition of symptoms is crucial to prevent the infection from spreading to the joints, heart, and nervous system.

Table of contents

• What is Lyme disease?
• How Lyme disease spreads
• Stages of Lyme disease
• Signs and symptoms
• Diagnosis and testing
• Treatment
• Prevention
• What to expect after treatment

What is Lyme disease?

Lyme disease is a bacterial infection that you can get from the bite of an infected tick. In the United States, it is caused by bacteria called Borrelia burgdorferi and rarely by Borrelia mayonii^[1]. It is the most common disease spread by ticks in the United States and among the most frequently diagnosed tick-borne infections worldwide^[3].

The disease got its name from Lyme, Connecticut, where it was first identified in the 1970s after a cluster of cases appeared in that area^[8].

How Lyme disease spreads

Lyme disease bacteria are spread to humans through the bite of infected blacklegged ticks, also called deer ticks^[1]. These ticks are very small, ranging in size from that of a poppy seed to a sesame seed, depending on their life stage. They are usually black with areas of reddish-brown or white on their backs^[5].

The ticks that spread Lyme disease are usually found in wooded, grassy, or brushy areas. In the United States, they live mainly in the Northeast, mid-Atlantic, and upper-Midwest regions, as well as the Pacific coast, especially northern California^[1][4]. In general, an infected tick must be attached to your body for more than 24 hours to spread the bacteria to you^[1][5].

Ticks can attach to any part of your body, but they are often found in hard-to-see areas such as your groin, armpits, and scalp^[4]. Most tick bites happen in the warmer months from April to September, when ticks are most active and people spend more time outdoors. However, you can get bitten during other times of the year, especially if temperatures are warmer than usual^[4].

Stages of Lyme disease

Lyme disease progresses through three stages if left untreated^[3][5]:

Early localized disease occurs between one and 28 days after the tick bite. This is the initial stage when the skin at the site of the tick bite becomes infected with the bacteria^[5][7].

Early disseminated disease develops three to 12 weeks after the initial infection. During this stage, the infection can spread through the bloodstream to other parts of your body, including your nervous system and heart^[5].

Late disease may occur months after the initial infection if the disease remains untreated. This stage can affect multiple body systems and lead to more serious complications^[5].

The stages can overlap, and some people may present with a later stage without having experienced symptoms of earlier disease^[3].

Signs and symptoms

Early symptoms

Early symptoms of Lyme disease usually appear between 3 to 30 days after an infected tick bites you^[1][4]. The most distinctive early sign is a red rash called erythema migrans. This rash starts as a small, red spot at the site of the tick bite and expands over several days or weeks, forming a circular, triangular, or oval shape. It may look like a bullseye, with a red ring surrounding a clear center area^[2][5]. The rash is usually not painful or itchy, though it may feel warm to the touch^[1][7].

However, it is important to know that not everyone with Lyme disease develops this rash. It appears in about 7 to 8 out of 10 infected people^[5][8]. The most common form of the rash is a uniformly red, round or oval rash that expands to greater than 2 inches in diameter, not the classic bullseye pattern^[7].

Other early symptoms can include^[1][4][7]:

• Fever and chills
• Headache
• Fatigue and malaise
• Muscle and joint aches
• Stiff neck
• Swollen lymph nodes

These symptoms can resemble the flu, but Lyme disease is not associated with typical cold-like symptoms such as a runny nose, prominent cough, or prominent diarrhea^[7].

Later symptoms

If the infection is not treated, it can spread to other parts of your body. Symptoms that may develop include^[1][4][5]:

• Multiple rashes on other areas of your body
• Facial palsy, which is a weakness in the muscles of one or both sides of your face that can cause drooping
• Severe headaches and neck stiffness
• Heart palpitations, which are feelings that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast
• An irregular heartbeat (a condition called Lyme carditis)
• Episodes of dizziness or shortness of breath
• Numbness or tingling in the hands or feet
• Shooting pains in the body
• Arthritis with severe joint pain and swelling, especially in the knees and other large joints

Late-stage symptoms

Symptoms of untreated late Lyme disease may include^[5]:

• Swollen and painful joints (arthritis) that comes and goes, typically affecting large joints like your knees
• Difficulty concentrating or other mental changes
• Damage to nerves in your skin, muscles, and organs
• Inflammation of the tissue covering your brain and spinal cord (meningitis)
• The bacteria invading your brain and spinal cord (encephalopathy)

Diagnosis and testing

To diagnose Lyme disease, your healthcare provider will consider^[4]:

• Your symptoms
• How likely it is that you were exposed to infected blacklegged ticks
• The results of any lab tests

If you live in an area where Lyme disease is common and you have the characteristic rash, that might be enough for a diagnosis. The diagnosis usually depends on a review of all signs and symptoms, a history of known or possible exposure to ticks, and blood tests^[10].

Most Lyme disease tests check for antibodies made by your body in response to the infection. These antibodies can take several weeks to develop. If you are tested right away after a tick bite, the test may not show that you have Lyme disease even if you do have it. So you may need to have another test later^[4].

The CDC recommends the use of FDA-cleared antibody tests for laboratory diagnosis of Lyme disease. The recommended testing approach is a two-step process^[1][3]. Laboratory testing is helpful if used correctly and performed with FDA-cleared tests^[1].

Treatment

Lyme disease is treated with antibiotics. The earlier you are treated, the better your chances of recovering quickly and completely^[1][9].

Antibiotic treatment

People treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely^[9]. The antibiotics most commonly used to treat Lyme disease include^[9][11]:

• Doxycycline – a tetracycline antibiotic and the first-line standard of care treatment for adults with Lyme disease
• Amoxicillin – a penicillin-like antibiotic
• Cefuroxime axetil (Ceftin) – a second-generation cephalosporin

The standard treatment is an antibiotic taken as a pill. Treatment usually lasts 10 to 14 days, though it may be longer depending on your symptoms^[9][10]. It is important to take all pills as directed, even if you are feeling better^[10].

Doxycycline is also effective against some other tick-borne illnesses, including anaplasmosis and ehrlichiosis^[14]. The antibiotic used and the length of treatment depends on many factors, including your symptoms, age, allergies, and whether you are pregnant^[9].

Intravenous antibiotics

For more serious cases of Lyme disease, your healthcare provider may prescribe an antibiotic given directly into a vein, called an intravenous (IV) antibiotic. This treatment may be used if you have^[10][11]:

• Long-lasting arthritis
• Disease affecting the nervous system, such as meningitis
• Disease affecting the heart

Preventive antibiotics after a tick bite

In general, the CDC does not recommend antibiotics after tick bites to prevent tick-borne diseases. However, in certain circumstances, a single dose of doxycycline after a tick bite may lower your risk of Lyme disease^[9].

Your provider may prescribe an antibiotic as a preventive measure only if all three of these conditions occur^[10]:

• The biting tick is known to be a deer tick
• You live in or recently visited an area where Lyme disease is common
• The tick was attached to the skin for 36 hours or more

Potential side effects

Within 24 hours of beginning antibiotic treatment, you may experience symptoms including fever, chills, nausea and vomiting, headache, increased heart rate, low blood pressure, flushing, and muscle aches and pain. This is called a Jarisch-Herxheimer reaction and occurs when the antibiotics start to kill the bacteria. This reaction typically occurs within a few hours of starting the antibiotic and usually goes away within 24 hours^[11][14].

Doxycycline can increase your sensitivity to the sun, making you burn more easily. It is best to avoid sun exposure when possible while on doxycycline. If you need to go outside, use sunscreen, a hat, or protective clothing^[14].

All antibiotics can cause gastrointestinal side effects, especially when used for longer periods. These include nausea, vomiting, abdominal pain, and diarrhea. The most common side effect of penicillin antibiotics is diarrhea, and occasionally even serious cases caused by the bacteria Clostridium difficile. This bacterial overgrowth occurs because antibiotics kill the good bacteria in your gut. It can be helpful to use probiotics to restore the good bacteria^[11].

Prevention

The best defense against Lyme disease is to prevent tick bites. This will reduce your risk of other tick-borne diseases as well^[1].

Protecting yourself from ticks

When outdoors in areas where ticks may live, take these steps^[20]:

• Wear protective clothing treated with tick pesticides such as permethrin
• Treat your skin with a tick repellent such as DEET
• Stay on marked trails and out of tall grass and leaf litter
• Wear long sleeves and pants, and tuck pants into socks

After being outdoors

After spending time outdoors in areas where ticks may be present^[20]:

• Perform daily tick checks, especially after coming in from outdoors
• Shower as soon as possible
• Put clothes in the dryer on high heat for 15 minutes
• Check hard-to-see areas such as your groin, armpits, and scalp

Removing ticks

If you find a tick attached to your skin, remove it as soon as possible. Removing ticks promptly reduces the risk of infection^[20]:

• Grasp the tick’s mouthparts against the skin using pointed tweezers
• Pull steadily without twisting until you can ease the tick head straight out of the skin
• Do not squeeze or crush the body of the tick, as this may force infected fluid into the skin
• Do not apply substances such as petroleum jelly, nail polish, or a lighted match to the tick while it is attached
• Once removed, wash the wound site and your hands with soap and water, and apply rubbing alcohol or antiseptic to the site

After removing a tick, observe the bite site over the next two weeks for any signs of an expanding red rash or flu-like symptoms. If a rash appears, take a photo, write down the date, and call your doctor immediately^[20].

Creating a tick-free zone

You can reduce ticks around your home by creating a tick-free zone. Keep your yard well-maintained, remove leaf litter, and keep grass short^[20].

What to expect after treatment

The prognosis after early treatment of Lyme disease is generally very good. Most patients with early Lyme disease infection recover with antibiotics and return to their normal state of health^[11]. However, the prognosis worsens when diagnosis and treatment are delayed^[11].

Post-treatment symptoms

After treatment, some patients may still have symptoms that last more than 6 months. This is called post-treatment Lyme disease syndrome (PTLDS)^[4]. Somewhere between 5% and 15% of people diagnosed with Lyme disease go on to develop PTLDS^[17].

A research study found that even when Lyme disease patients were diagnosed early and promptly treated, 14% of the patients developed post-treatment Lyme disease. These patients have persistent symptoms including severe fatigue, body pain, and cognitive challenges^[11][18].

If you continue to experience symptoms after treatment, it is important to let your healthcare provider know. There are many medical conditions that can cause similar symptoms, so your provider will need to run tests and rule out other possibilities^[17].

Managing ongoing symptoms

Once antibiotics resolve the infection, you can support your recovery by^[17]:

• Eating a healthy diet and limiting sugar intake
• Getting plenty of rest
• Exercising at least three times a week for at least 30 minutes each day
• Reducing stress
• Using anti-inflammatory medication when necessary

The damage Lyme disease causes to your nerves or muscles will heal over the course of several months^[17]. For many people with Lyme disease, a brief course of antibiotics is all that is needed to recover and move along^[16].