Lyme Disease

What is Lyme disease?

From: MedlinePlus, National Library of Medicine

Lyme disease is a bacterial infection you get from the bite of an infected tick. At first, Lyme disease usually causes symptoms such as a rash, fever, headache, and fatigue. But if it is not treated early, the infection can spread to your joints, heart, and nervous system. Prompt treatment can help you recover quickly.

What causes Lyme disease?

From: MedlinePlus, National Library of Medicine

Lyme disease is caused by bacteria. In the United States, this is usually a bacterium called Borrelia burgdorferi. It spreads to humans through the bite of an infected tick. The ticks that spread it are blacklegged ticks (or deer ticks). They are usually found in the:

• Northeast
• Mid-Atlantic
• Upper Midwest
• Pacific coast, especially northern California

These 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. Usually, the tick must be attached to you for more than 24 hours to spread the bacterium to you.

Who is more likely to get Lyme disease?

From: MedlinePlus, National Library of Medicine

Most tick bites happen in the warmer months (April-September), when ticks are most active and people spend more time outdoors. But you can also get bitten during the rest of the year, especially if the temperatures are warmer than usual.

Most tick bites happen in the summer months when ticks are most active and people spend more time outdoors. But you can get bitten in the warmer months of early fall, or even late winter if temperatures are unusually high. And if there is a mild winter, ticks may come out earlier than usual.

What are the symptoms of Lyme disease?

From: MedlinePlus, National Library of Medicine

Early symptoms of Lyme disease start between 3 to 30 days after an infected tick bites you. The symptoms can include:

If the infection is not treated, it can spread to your joints, heart, and nervous system. The symptoms may include:

• A red rash called erythema migrans (EM). Most people with Lyme disease get this rash. It gets bigger over several days and may feel warm. It is usually not painful or itchy. As it starts to get better, parts of it may fade. Sometimes this makes the rash look like a "bull's-eye."
• Fever
• Chills
• Headache
• Fatigue
• Muscle and joint aches
• Swollen lymph nodes ("swollen glands")
• Severe headaches and neck stiffness.
• More EM rashes on other areas of your body.
• Facial palsy, which is a weakness in your facial muscles. It can cause drooping on one or both sides of your face.
• Arthritis with severe joint pain and swelling, especially in your knees and other large joints.
• Pain that comes and goes in your tendons, muscles, joints, and bones.
• Heart palpitations, which are feelings that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast.
• An irregular heart beat (Lyme carditis).
• Episodes of dizziness or shortness of breath.
• Inflammation of the brain and spinal cord.
• Nerve pain.
• Shooting pains, numbness, or tingling in the hands or feet.

How is Lyme disease diagnosed?

From: MedlinePlus, National Library of Medicine

To make a diagnosis, your health care provider will consider:

• Your symptoms
• How likely it is that you were exposed to infected blacklegged ticks
• How likely it is that you could have other illnesses that cause similar symptoms
• The results of any lab tests

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

What are the treatments for Lyme disease?

From: MedlinePlus, National Library of Medicine

Lyme disease is treated with antibiotics. The earlier you are treated, the better; it gives you the best chance of fully recovering quickly.

After treatment, some patients may still have pain, fatigue, or difficulty thinking that lasts more than 6 months. This is called post-treatment Lyme disease syndrome (PTLDS). Researchers don't know why some people have PTLDS. There is no proven treatment for PTLDS; long-term antibiotics have not been shown to help. However, there are ways to help with the symptoms of PTLDS. If you have been treated for Lyme disease and still feel unwell, contact your health care provider about how to manage your symptoms. Most people do get better with time. But it can take several months before you feel better.

Can Lyme disease be prevented?

From: MedlinePlus, National Library of Medicine

To prevent Lyme disease, you should lower your risk of getting a tick bite:

• Avoid areas where ticks live, such as grassy, brushy, or wooded areas. If you are hiking, walk in the center of the trail to avoid brush and grass.
• Use an Environmental Protection Agency (EPA)-registered insect repellent when you go outdoors. They are evaluated to make sure they are safe and effective. Make sure that the repellant has one of these ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. It is important to follow the instructions on the label.
• Treat your clothing and gear with a repellant containing 0.5% permethrin
• Wear light-colored protective clothing, so you can easily see any ticks that get on you
• Wear a long-sleeved shirt and long pants. Also tuck your shirt into your pants and your pant legs into your socks.
• Check yourself, your children, and your pets daily for ticks. Carefully remove any ticks you find.
• Take a shower and wash and dry your clothes at high temperatures after being outdoors

Genetic causes described in the linked summary

From: MedlinePlus Genetics

Lyme disease is caused by infection with bacteria rather than by genetic changes. The risk of developing Lyme disease is influenced by a variety of lifestyle and environmental factors that reflect how likely a person is to get bitten by an infected tick, such as where a person lives, how much time is spent outdoors, and the time of year. While there is no evidence that genetic factors play a role in susceptibility to Lyme disease, such factors may affect the severity of the disease, particularly whether antibiotic-refractory Lyme arthritis develops.

The signs and symptoms of Lyme disease result from the body's immune response to the bacteria. When the body recognizes foreign invaders, such as bacteria, it stimulates inflammation to help fight the infection. This inflammation causes the skin irritation; flu-like symptoms; and neurological, cardiac, and joint problems that characterize Lyme disease.

Certain genes that help mediate the body's immune response have been associated with the development of antibiotic-refractory Lyme arthritis. Particular variants in these genes are found more often in people with this complication than in those who do not develop it.

Some of the genes thought to be associated with the development of antibiotic-refractory Lyme arthritis provide instructions for making proteins called Toll-like receptors. As one of the first lines of defense against infection, Toll-like receptors recognize patterns that are common to many foreign invaders, rather than recognizing a specific invader, and stimulate a quick immune response that triggers inflammation. Some variants of certain Toll-like receptor genes are thought to overstimulate the body's immune response to the Lyme disease bacteria, contributing to the joint inflammation of antibiotic-resistant Lyme arthritis.

Other genes thought to be associated with antibiotic-resistant Lyme arthritis belong to a gene family called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders. Each HLA gene has many different variations, allowing each person's immune system to react to a wide range of proteins. The proteins produced from HLA genes attach to protein fragments and display them to the immune system. If the immune system recognizes the fragment as foreign or abnormal, it triggers an immune response. Some evidence suggests that certain variations of HLA genes contribute to an inappropriate immune response that causes the body to react to one of its own normal proteins. The resulting inflammation may contribute to development of antibiotic-refractory Lyme arthritis.

Inheritance described in the linked summary

From: MedlinePlus Genetics

Lyme disease cannot be inherited. The risk of certain complications of the condition may be influenced by inherited genetic factors, but the inheritance pattern is unknown.

Which doctor should you see?

The suggested department for discussing Lyme Disease is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.