How Do Doctors Diagnose Lyme Disease?
In areas where the ticks that carry Lyme disease are found, when a patient comes to a doctor with probable erythema migrans (the rash that appears where the tick bite occurred), blood tests are performed to diagnose the condition, including the following:
Other tests that may be indicated include the following:
What Are the Signs and Symptoms of Lyme Disease?
Symptoms and signs of Lyme disease vary with the stage of the disease. Symptoms of the early stage of Lyme disease include the following:
- Feeling unwell (malaise)
- Muscle and joint pains
- The rash usually appears within a month of getting bitten.
- Rash appears red, but the center may be a persons normal skin color.
- The rash may expand over a few days.
- The rash may look like a “bulls eye.”
As Lyme disease progresses, symptoms and signs may include the following:
In patients in the late stage of the disease, the most common symptom is arthritis, located mostly in large joints, especially the knee. Symptoms of Lyme arthritis include warmth, swelling from fluid, and limited range of motion.
Lyme disease is caused by infection with the spirochete Borrelia burgdorferi. In regions of the U.S. where Lyme disease is common, risk factors for getting bitten by a tick include
Ticks can also attach to pets (including dogs and cats) that may bring them into the home. The pet may become infected with Lyme disease. If the tick does not attach to the pet, it can attach to a human and transmit the infection.
Do antibodies to B. burgdorferi determine active infection?
In untreated animals, antibodies to OspC and/or OspF are indicators of infection with B. burgdorferi. Many infected animals don’t show clinical signs and maintain constant antibody levels to the pathogen. It is believed that many animals can control the persistent infection. However, increasing antibody values indicate re-activation of or re-infection with the pathogen.
In treated animals, antibody levels decrease slowly and are usually still detectable for several months if treatment was successful.