Lyme disease is the leading tick-borne disease in the United States. It's caused by a type of bacteria found in small animals like mice and deer. Ixodes ticks (also called black-legged or deer ticks) that feed on these animals can then spread the bacteria to people through tick bites.
Signs of Lyme disease:
A circular rash at the site of the tick bite, usually within one to two weeks of infection, often is the first sign of infection. Although a rash is considered typical of Lyme disease, many people never develop one.
Common characteristics of the rash include:
- A "bull's-eye" appearance, with a central red spot surrounded by clear skin ringed by an expanding red rash
- It can also appear as an expanding ring of solid redness
- It's usually flat and painless
- Sometimes, the rash can be warm to the touch, itchy, scaly, burning or prickling
- Along with the rash, a person may have flu-like symptoms such as fever, tiredness, headache and muscle aches
Left untreated, symptoms of the initial illness may go away on their own. But in some people, the infection can spread to other parts of the body. Symptoms of this stage of Lyme disease usually appear within several weeks after the tick bite, even in someone who didn't have the initial rash. A person might feel very tired and unwell, or have more areas of rash that aren't at the site of the bite.
The last stage of Lyme disease happens if the early stages were not found or treated. Symptoms of late Lyme disease can appear anytime from weeks to years after an infectious tick bite. In kids, this is almost always in the form of arthritis, with swelling and tenderness, particularly in the knee or other large joints. Having such a wide range of symptoms can make Lyme disease hard for doctors to diagnose, although blood tests can look for signs of the body's reaction to Lyme disease.
When to call your doctor
If you think you could be at risk for Lyme disease or have been bitten by a tick, call your doctor. This is especially true if you develop a red-ringed rash, flu-like symptoms, joint pain or a swollen joint, or facial paralysis. That way you can get further evaluation and treatment, if necessary, before the disease progresses too far.
Lyme disease is usually treated with a two to four week course of antibiotics. Cases that are diagnosed quickly and treated with antibiotics almost always have a good outcome. A person should be feeling back to normal within several weeks after beginning treatment.
It's important to know and watch for symptoms of Lyme disease because ticks are hard to find and it's easy to overlook a tick bite — in fact, many people who get Lyme disease don't remember being bitten. The good news is that most tick bites don't result in Lyme disease and if you practice caution you can avoid being bitten altogether!