The danger of tick bites
While most tick bites are harmless, several species can cause life-threatening diseases. Two of these well-known diseases are Rocky Mountain Spotted Fever and Lyme disease. Ticks can also transmit tularemia (a plague-like disease in rodents that can be transmitted to man), relapsing fever, and ehrlichiosis (an abrupt illness consisting of fever, rash, nausea, vomiting, and weight loss).
What is Lyme disease?
Lyme disease (LD) is a multistage, multisystem bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral shaped bacterium that is most commonly transmitted by a tick bite. The disease takes its name from Lyme, Connecticut, where the illness was first identified in the United States in 1975.
According to the Centers for Disease Control and Prevention (CDC), Lyme disease continues to be a rapidly emerging infectious disease, and is the leading cause of all insect-borne illness in the US. According to the CDC, LD cases more than doubled during the surveillance period of 1992 to 2006. In 2008, there were nearly 29,000 confirmed cases and nearly 6,300 probable cases of LD.
What types of ticks transmit LD?
Ixodes scapularis (northeastern and north-central U.S., black-legged deer tick)
Ixodes pacificus (Pacific coastal U.S., Western black-legged tick)
Ticks prefer to live in wooded areas, low-growing grasslands, seashores, and yards. Depending on the location, anywhere from less than 1 percent to more than 50 percent of the ticks are infected with spirochetes.
Although Lyme disease is a year-round problem, April through October is considered tick season. Cases of Lyme disease have been reported in nearly all states in the U.S. and in large areas in Europe and Asia.
What are the symptoms of Lyme disease?
The list of possible symptoms is long, and symptoms can affect every part of the body. The following are the most common symptoms of Lyme disease. However, each individual may experience symptoms differently.
The primary symptom is a red rash that:
Can appear several days after infection, or not at all.
Can last a few hours or up to several weeks.
Can be very small or very large (up to 12 inches across).
Can mimic such skin problems as hives, eczema, sunburn, poison ivy, and flea bites.
Can itch or feel hot, or may not be felt at all.
Can disappear and return several weeks later.
Several days or weeks after a bite from an infected tick, a patient usually experiences flu-like symptoms such as the following:
Aches and pains in muscles and joints
Low-grade fever and chills
After several months, arthritis-like symptoms may develop, including painful and swollen joints.
Other possible symptoms may include the following:
Poor motor coordination
Some people may develop post-Lyme disease syndrome (PLDS), a condition also known as chronic Lyme disease, characterized by persistent musculoskeletal and peripheral nerve pain, fatigue, and memory impairment.
How is Lyme disease diagnosed?
Lyme disease is difficult to diagnose because symptoms are not consistent and may imitate other conditions. The primary symptom is a rash, but it may not be present in up to 20 percent of cases.
Diagnosis for Lyme disease is a clinical one and must be made by a physician experienced in recognizing LD. Diagnosis is usually based on symptoms and a history of a tick bite. Testing is generally done to eliminate other conditions and may be supported through blood and laboratory tests, although these tests are not absolutely reliable for diagnosing LD.
Research is underway to develop and improve methods for diagnosing LD.
The symptoms of Lyme disease may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
What is the treatment for Lyme disease?
Specific treatment for Lyme disease will be determined by your doctor based on:
Your age, overall health, and medical history
Extent of the symptoms
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the condition
Your opinion or preference