Lyme disease is a bacterial infection that’s caused by a bite from a blacklegged tick.

Early disseminated Lyme disease is the phase of Lyme disease in which the bacteria that cause this condition have spread throughout the body. This stage can occur days, weeks, or even months after an infected tick bites you.

There are three stages of Lyme disease. Early disseminated Lyme disease is the second stage.

  • Stage 1: Early localized Lyme disease. This occurs within several days of a tick bite. Symptoms may include redness at the site of the tick bite along with fever, chills, muscle aches, and skin irritation.
  • Stage 2: Early disseminated Lyme disease. This occurs within weeks of a tick bite. The untreated infection begins spreading to other parts of the body, producing a variety of new symptoms.
  • Stage 3: Late disseminated Lyme disease. This occurs months to years after an initial tick bite, when bacteria have spread to the rest of the body. During this stage, many people experience cycles of arthritis and joint pain along with neurological symptoms such as shooting pain, numbness in the extremities, and problems with short-term memory.

The onset of early disseminated Lyme disease can begin days, weeks, or months after a person is bitten by an infected tick. The symptoms reflect the fact that the infection has begun to spread from the site of the tick bite to other parts of the body.

At this stage, the infection causes specific symptoms that may be intermittent. They are:

Lyme disease is caused by Borrelia burgdorferi bacteria. You can contract the infection when a tick that carries the bacteria bites you. Typically, blacklegged ticks and deer ticks spread the disease. These ticks collect the bacteria when they bite mice or deer.

These tiny ticks spread the infection by attaching themselves to various parts of your body. They’re about the size of a poppy seed and favor hidden areas such as the groin, armpits, and scalp. Often, they can remain undetected in these spots.

Most people who develop Lyme disease report that they never saw a tick on their body. The tick transmits bacteria after being attached for about 36 to 48 hours.

Early disseminated Lyme disease occurs within a few weeks of a tick bite, after the initial infection goes untreated.

You’re at risk for early disseminated Lyme disease if you’ve been bitten by an infected tick and remain untreated during stage 1 of Lyme disease.

You’re at an increased risk of contracting Lyme disease in the United States if you live in one of the areas where most Lyme disease infections are reported. They are:

  • any of the Northeastern states from Maine to Virginia
  • the north central states, with the highest incidence in Wisconsin and Minnesota
  • parts of the West Coast, primarily northern California

Certain situations also can increase your risk of coming into contact with an infected tick, such as:

  • gardening, hunting, hiking, or doing other outside activities in areas where Lyme disease is a potential threat
  • walking or hiking in high grass or wooded areas
  • having pets that may carry ticks into your home

In order to diagnose Lyme disease, a doctor will order a blood test that checks for titers, which are the level of antibodies to the bacteria that cause the disease.

The enzyme-linked immunosorbent assay (ELISA) is the most common test for Lyme disease. The Western blot test, another antibody test, was once used to confirm the ELISA results. Current recommendations from the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) state that a second ELISA test may be used to confirm Lyme disease.

The antibodies to B. burgdorferi can take anywhere from 4 to 6 weeks after infection to show up in your blood. As a result, people tested within the first few weeks of infection may test negative for Lyme disease. In this case, your doctor may choose to monitor your symptoms and test again at a later date to confirm the diagnosis.

If you’re in an area where Lyme disease is common, your doctor may be able to diagnose Lyme disease in stage 1 based on their clinical experience and your symptoms.

If your doctor suspects you have early disseminated Lyme disease and the infection has spread throughout your body, they may recommend testing potentially affected areas. These tests may include:

If you don’t get treatment at the early disseminated stage, the complications of Lyme disease can include damage to your joints, heart, and nervous system. However, if Lyme disease is diagnosed at this stage, symptoms can still be treated successfully.

If the disease progresses from the early disseminated stage to the late disseminated stage (stage 3) without treatment, it can lead to long-term complications. These may include:

When Lyme disease is diagnosed at the early localized stage or early disseminated stage, the standard treatment is a 10- to 28-day course of oral antibiotics. The most common medications used are:

Other antibiotics or intravenous (IV) medication may be necessary depending on your condition and additional symptoms.

You will likely have a rapid and complete recovery if you receive antibiotics in one of the early stages of Lyme disease.

If you receive a diagnosis and treatment with antibiotics at this stage, you can expect to be cured of Lyme disease. Without treatment, complications can occur. Treatments are available for the complications.

In rare cases, you may experience a continuation of Lyme disease symptoms after antibiotic treatment. This is called post-treatment Lyme disease syndrome (PTLDS).

Some people who were treated for Lyme disease report muscle and joint pain, cognitive difficulties, sleep issues, or fatigue after their treatments were finished.

The cause of this is unknown. However, researchers believe it may be due to an autoimmune response in which your immune system attacks healthy tissues. It may also be linked to an ongoing infection with the bacteria that causes Lyme disease.

The practices below can reduce your likelihood of contracting Lyme disease and having it progress to the early disseminated stage.

How to avoid contracting Lyme disease

By taking specific precautions, you can prevent coming into direct contact with infected ticks.

  • Use insect repellant on your clothing and all exposed skin when walking in wooded or grassy areas where ticks thrive.
  • Treat clothing and footwear with permethrin (Nix), an insect repellant that remains active through several washings.
  • Walk in the center of trails to avoid high grass when hiking.
  • After walking or hiking, change your clothes and perform a thorough check for ticks, focusing on the groin, scalp, and armpits.
  • Check your pets for ticks.

Contact a doctor if a tick bites you. You should be observed for 30 days for signs of Lyme disease.

How to prevent Lyme disease from progressing

Learn the symptoms of early Lyme disease so that you can seek treatment promptly if you contract the infection. If you get timely treatment, you can avoid the potential complications of early disseminated Lyme disease and later stages.

The symptoms of early Lyme disease can occur between 3 and 30 days after an infected tick bites you. Look for:

  • rash, such as:
    • a red, expanding bull’s-eye rash at the site of the tick bite
    • a round or oval rash that can be as wide as 6 to 8 inches
  • fatigue
  • chills
  • a general feeling of illness
  • itching all over your body
  • headache
  • dizziness
  • faintness
  • muscle or joint pain
  • neck stiffness
  • swollen lymph nodes