How Is Lyme Disease Diagnosed?

Borreliosis—more commonly called Lyme disease—is an illness caused by bacteria that you get when you are bitten by a certain type of tick. The tick that causes the disease is the black-legged tick, aka the deer tick. Removing an attached tick within 24 hours can greatly lower your chances of getting Lyme disease.

If you've been bit, healthcare providers will look for certain signs and symptoms to diagnose Lyme disease. Only some people develop the characteristic bulls-eye rash. Others may experience signs that are not as telling, such as flu-like symptoms, general fatigue, and joint pain. Blood testing is commonly used to help nail down a diagnosis.

Early signs and symptoms can show up anywhere within days to one month of the tick bite. Other symptoms can take months to manifest. The sooner you get checked out, the better. Here's what to know about how this disease is diagnosed.

Diagnostic Criteria

Diagnosing Lyme disease depends on several criteria. It usually takes a combination of symptoms, lab tests, and other information to make a diagnosis.

The symptom most commonly associated with Lyme disease is the bulls-eye rash, medically called erythema migrans. Around 70% to 80% of people with Lyme disease will develop this characteristic circular skin lesion, which can expand around the site of the bite. On lighter skin tones, the rash will appear red, whereas it may be less obvious on darker skin tones.

Healthcare providers generally look for these symptoms of Lyme disease, which can show up within three to 30 days after the tick bite:

• Round rash around the tick bite
• Fever
• Chills
• Headache
• Fatigue
• Muscle and joint aches
• Swollen glands (swollen lymph nodes)

If left untreated, Lyme disease can cause the following symptoms later on:

• Severe headaches and neck stiffness
  
• Rashes on other parts of your body
• Drooping of one or both sides of your face (facial palsy)
• Arthritis with severe joint swelling, especially in your knees
• Muscle, joint, bone, or tendon pain that comes and goes
• Irregular heartbeat (arrhythmia)
• Periods of feeling dizzy or short of breath
• Shooting pain, numbness, tingling in your hands or feet

Why Lyme Disease Is Hard To Diagnose

The symptoms of Lyme disease are not very specific. In other words, the symptoms don't clearly point to one particular disease but are broad enough to be any of several medical conditions.

Not everyone gets the telltale rash, and symptoms can point to more than one cause. Aches, pains, and fever could all be caused by a different type of infection, for example. Plus, other conditions like southern tick-associated rash illness can produce a rash very similar to that seen in Lyme disease.

That's why healthcare providers don't just rely on symptoms alone. They have to use other ways to diagnose Lyme disease as well. This includes asking patients about their history and performing diagnostic tests. The results help distinguish Lyme disease from other conditions like chronic fatigue syndrome and depression.

History

When you get a medical checkup after a tick bite, your healthcare provider will likely want to know parts of your history, in addition to your symptoms. One thing that will be very important is whether you've been in an area where Lyme disease is found. In the United States, Lyme disease is most common in the Northeast, Mid-Atlantic, upper Midwest, and Pacific Coast states.

You'll also want to share details about your medical history. For example, a skin rash could be a sign of other skin conditions, like contact dermatitis. Gout, rheumatoid arthritis, and cellulitis are also conditions that could present with symptoms similar to those of Lyme disease.

Blood Tests

Blood testing is fairly common to help diagnose Lyme disease. The sample is usually taken from a vein in your arm. The amount of blood needed for the test is small. Collecting the sample is a fairly quick procedure, taking usually less than five minutes.

The blood test looks for certain antibodies. Antibodies are immune system proteins that help ward off foreign invaders like harmful bacteria and viruses. If you have been exposed to the bacteria that causes Lyme disease, your body will make antibodies specific to those bacteria.

It may take a few weeks for your body to make enough of these antibodies to show up on a blood test. Blood tests will be the most accurate when they are taken at least 30 days after you had symptoms.

To be clear about antibodies, their presence in your blood doesn't necessarily mean that Lyme disease is causing your symptoms. You may have had Lyme disease before but could have recovered months or years ago. Your healthcare provider will advise you on the best course of action for your situation if you test positive.

If you live in an area where Lyme disease is very common, your healthcare provider may start you on treatment without waiting for the results of the blood test. However, most people with vague symptoms will need to be tested.

Other Tests

In some cases, your healthcare provider may want to test your cerebrospinal fluid (CSF). CSF is the fluid that circulates through your brain and spinal cord. Your healthcare provider will decide to do this test based on the results of your blood test. Results that indicated possible Lyme disease or that were unclear may warrant CSF testing.

A CSF test is also helpful if you have neurologic symptoms, ones affecting your nervous system. Such symptoms include neck stiffness or numbness in your hands or feet.

Like getting your blood drawn, the procedure for the CSF test takes only about five minutes. However, you may be asked to lie down for an hour or so afterward to prevent headaches.

The procedure is called a lumbar puncture, aka a spinal tap. The healthcare provider will numb an area on your back so you don't feel the insertion of a needle. This hollow needle goes in between two vertebrae (back bones) in your lower spine, and a fluid sample is collected.

Like with the blood test, there are very few risks to having a lumbar puncture. You may feel a little tenderness where the needle was inserted. Some bleeding or a headache is also normal. Talk to your healthcare provider if the headache is very painful.

Stages of Lyme Disease

There are three stages of Lyme disease. The first two stages are considered part of early infection and occur within days to months of the tick bite. Stage 3 is when persistent or chronic Lyme disease occurs and it usually happens within 12 months of the infection.

Stage 1

This stage usually happens within one to 28 days of a tick bite and is characterized by early localized disease. You may see the classic erythema migrans rash around the bite, and you could have a low-grade fever.

If you get it, the rash will generally show up five to seven days after the bite. It could burn, itch, or not bother you at all. Flu-like symptoms are not uncommon either. You could have a slight fever, muscle pain, neck stiffness, and headache. Eye redness and tearing could also occur.

Stage 2

This stage occurs three to 12 weeks after the infection and is referred to as disseminated. By this time, the disease has spread from the site of the tick bite to other parts of the body.

During this stage, you may feel generally unwell and have a fever, dizziness, headache, muscle pain, chest pain, palpitations, or shortness of breath. Double vision, eye pain, and joint pain can also occur. Neurologic symptoms that occur during stage 2 could warrant a CSF test.

Stage 3

Also known as late or chronic Lyme disease, stage 3 refers to symptoms that persist for many months or even years after the infection. The key symptom in this stage is arthritis which usually affects the knees. However, cognitive processes, your nervous system, and heart health can also be affected.

Treatment After Diagnoses

The earlier Lyme disease is diagnosed, the easier it is to cure. The specific treatment will depend, in part, on how the symptoms are showing up.

In general, two to three weeks of oral antibiotics usually help patients feel better and eliminate all symptoms. If Lyme disease goes untreated for several months, however, a longer course of drugs is often needed. In extreme cases, antibiotics may also be given through an intravenous (IV) injection—administered into your veins.

Post-Treatment Lyme Disease Syndrome

A small number of people, only about 5%, develop post-treatment Lyme disease syndrome. This is when symptoms of Lyme disease linger for six months or more even after treatment. The symptoms can include persistent fatigue (tiredness), pain, and aches in joints and muscles.

Healthcare providers aren't sure what causes post-treatment Lyme disease syndrome. Some believe that symptoms are due to other tick-borne illnesses, or chronic conditions like rheumatoid arthritis.

There hasn't been any evidence showing benefits from treatments like long-term antibiotic therapy. Most people eventually recover on their own without lasting health effects.

A Quick Review

Lyme disease is a tick-borne illness that may cause rash, fatigue, and flu-like symptoms. Symptoms may often go unnoticed or be mistaken for something else at first. They can show up within days, weeks, or months after the bite.

Diagnosing Lyme disease can be difficult because the symptoms are not much different from those of other conditions. Along with wanting to know about your symptoms and where you've been, your healthcare provider may want to run a blood test, or sometimes a CSF test, to confirm a suspected diagnosis.

When detected early, Lyme disease can often be cured through antibiotic treatment. Long-term effects like pain and fatigue occur in a small number of people but usually go away eventually.

To prevent Lyme disease, protect yourself from tick bites when you're in an area where Lyme disease is common. If you have a bite or think you may have been bitten and have symptoms, get checked out by a healthcare provider.