Lyme Disease
Amy Movius, MD
May 5, 2009
Lyme disease is an infection that usually affects small animals, but it can also infect people. The infection can spread to humans when a tick bites an infected animal, “picks up” the infection, and then delivers or “carries” the infection to a person who is later bitten by that same tick. The peak season for Lyme disease is late spring through summer –yep, right about now. This is a function of both the tick life cycle, as well as the increase amount of outdoor time that we enjoy with the nice weather. New England has one of the highest rates of Lyme disease in the country and the reported cases in Maine have been rising steadily over the last several years, with more than 500 confirmed cases in 2007.
As with many health conditions, the best defense is a good offense; the most effective way to avoid Lyme disease is to avoid any tick exposure. This means avoiding wooded or bushy areas, locations with high grass or lots of leaf litter. However, this is impractical for many of us. Preventing bites and recognizing exposure to ticks early are much more realistic and relatively simple ways to protect ourselves.
Our clothing is our first line of defense. Wearing long sleeves and long pants in outdoor areas where ticks may be present is a good start. If the clothing is light colored, it will be easier to see ticks as well. Pants can be tucked into socks and even taped to prevent ticks from climbing up the inside of pant legs. Clothes can also be treated with permethrin, available at outdoors/camping stores, to repel ticks from attaching to them. After clothes are worn outdoors, washing in hot water and drying on high heat should eliminate any ticks you may have missed.
Tick repellents containing 20-30% DEET can be applied to the skin also. At the end of every day outdoors, you should do a tick “body check” looking for any critters who may have attached themselves despite your efforts. If you find a tick, you should carefully remove it by gently pulling it straight out with tweezers. Wash the area well and use a topical antiseptic afterwards. Use of petroleum jelly, nail polish and other home treatments are NOT recommended. Removing ticks quickly is very helpful in preventing Lyme disease as it is extremely unlikely to acquire infection from a tick that has been on the body 24 hours or less.
Treating pets with tick repellents and removing ticks from them promptly is also very important. Though your pet cannot give you Lyme disease, they may be giving the ticks that can a ride straight into your house.
If a tick bite is noticed, routine antibiotic use is NOT recommended, rather careful watching of the bite location is. The most common finding in Lyme disease is an expanding red rash around the bite site. It can occur from days to a month after the bite and is usually not painful. Any rash around a bite should be seen by a health provider, even if you otherwise feel fine, at which time antibiotics can be administered. Many persons who receive no treatment will develop other symptoms, even months later, especially intermittent arthritis of the large joints. A small number of infected people can develop even more serious symptoms and a few may develop a chronic condition, despite antibiotic treatment.
References:
www.maine.gov.cdc
www.cdc.gov
The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America. Clinical Infectious Diseases 2006;43: (1 November)