May is Lyme Disease Awareness Month
Lyme disease is an infection caused by Borrelia burgdorferi bacteria. The bacteria are transmitted to humans through a bite from a blacklegged tick (deer tick), which becomes infected from feeding on deer or mice. The bacteria eventually find their way into the bloodstream. Only a minority of blacklegged tick bites lead to Lyme disease.
Symptoms and signs can occur anywhere from 3 to 30 days after the bite, or they can appear even months later, depending on the stage of the infection. Ticks must be attached for 36 to 48 hours in order to transmit Lyme disease. Most cases can be successfully treated with antibiotics. But if left untreated, the infection can spread to joints, heart, and the nervous system.
Three Phases of Lyme Disease
Lyme disease can generally be divided into three phases: early localized, early disseminated, and late disease. The signs and symptoms of each stage can overlap. Some patients may present as later stage Lyme disease without experiencing the earlier phase signs and symptoms
Early Localized Disease
Early localized disease starts one to two weeks after the tick bite. The bacteria are localized. Erythema migrans, a circular red rash, usually appears at the site of the bite within 7-10 days.
It is not always present.
Other signs and symptoms may appear, including the following:
- Anorexia (loss of appetite)
- Arthralgia (pain in a joint)
- Myalgia (muscle pain)
Early Disseminated Disease
Early disseminated disease occurs weeks to several months after the tick bite when bacteria have spread throughout the body. Cardiac and neurological involvement is often present. Symptoms and signs may include:
- Flu-like symptoms – chills, fever, fatigue, headache, and joint pain
- Bell palsy (facial paralysis)
- Meningitis (inflammation of the membrane covering the spinal cord and brain)
- Arthralgia (pain in the joint)
- Neuropathy (disease of the nerve)
- Radiculopathy (disease of the nerve roots)
- Arrhythmias (disturbance of the rhythm of the heart)
Late Lyme disease occurs when the infection wasn’t treated during phases 1 or 2 of the disease and can occur months, or years, after the tick bite. The bacteria have spread throughout the body. Symptoms and signs may include:
- Arthritis (inflammation of the joints)
- Fibromyalgia (muscle and soft tissue syndrome)
- Encephalopathy (cognitive disturbances such as short-term memory loss, difficulty concentrating, problems following conversations)
- Polyneuropathy (disease of many nerves)
Laboratory tests to identify antibodies to the bacteria can help confirm or rule out the diagnosis. These tests are most reliable a few weeks after infection. They include Enzyme-linked immunosorbent assay (ELISA) test to detect antibodies to B. burgdorferi. If the ELISA test is positive a western blot test is usually done to confirm the diagnosis. Laboratory tests are not recommended for patients who do not have symptoms typical of Lyme disease.
Oral antibiotics are used to treat Lyme disease. In general, recovery will be quicker and more complete the sooner treatment begins. People treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely.
Lyme disease was first described in 1975 when unusually large numbers of children were diagnosed with juvenile rheumatoid arthritis in and near Lyme, CT. Researchers discovered that the nature of Lyme disease often involves other body systems. The number of reported cases in the US is increasing, with recent CDC studies suggesting 300,000 people per year are diagnosed with the disease.
The Centers for Disease Control and Prevention (CDC) confirmed that in 2015, 95% of Lyme disease cases occurred in 14 states located in the Northeast and Midwest. Now, however, the “blacklegged” tick invasion has spread to southern and western U.S. as well as to Canada, bringing with it the possibility of Lyme Disease. May is Lyme Disease Awareness Month. Most identified cases of Lyme disease occur during June, July, August, and right now is the best time to learn how to avoid tick bites and what to do if you are bitten. Use these two websites to learn more: Preventing Tick Bites on People and Tick Removal and Testing. Have a safe summer!
Watch this 2-minute video to review the signs and symptoms of Lyme disease.
Medical Terminology Tips
Lyme disease: An is an eponym named after Lyme, CT. When using the term – Lyme is capitalized and disease is not – as in Lyme disease.
Bell palsy: The modern trend, for medical terminology, is to use the non-possessive form of eponyms as in Bell palsy instead of Bell’s palsy. The ‘p’ in palsy remains lower case.
Blacklegged vs black-legged: Both spellings are acceptable. It appears that blacklegged is more commonly used in medical writings.
References: Online UpToDate
Medical term definitions are from Exploring Medical Language 10th Edition.
Pass this post on to others.