Patient education: Lyme disease prevention (Beyond the Basics)

LYME DISEASE OVERVIEW — Several measures may help prevent tick bites and tick-borne illnesses, such as Lyme disease. These include personal precautions, such as wearing long pants and long-sleeved shirts, wearing tick repellent, and also making changes to areas in your yard where deer ticks are likely to live.

The diagnosis and treatment of Lyme disease are discussed separately. (See "Patient education: Lyme disease symptoms and diagnosis (Beyond the Basics)" and "Patient education: Lyme disease treatment (Beyond the Basics)".)

More detailed information about Lyme disease is available by subscription. (See "Prevention of Lyme disease" and "Evaluation of a tick bite for possible Lyme disease" and "Epidemiology of Lyme disease" and "Clinical manifestations of Lyme disease in adults" and "Lyme disease: Clinical manifestations in children" and "Diagnosis of Lyme disease" and "Treatment of Lyme disease" and "Prevention of arthropod and insect bites: Repellents and other measures".)

PERSONAL PRECAUTIONS — You can take precautions to prevent ticks from attaching to your skin if you know that you will be spending time in tick-infested areas where Lyme disease and/or other tick-borne illnesses are common.

Wear protective clothing — Ticks can be kept away from the skin by wearing long-sleeved shirts and long trousers tucked into socks. Wearing light-colored clothing will make it easier to spot ticks on clothing. To further reduce the risk of being exposed to a tick, you can also pre-treat clothing with permethrin. (See 'Permethrin' below.)

Shower — Showering within two hours of potential exposures to ticks can reduce the chance of being infected with Lyme disease by washing away ticks before they have had a chance to bite and attach firmly.

Use a tick repellent or tick-killing product — Several different commercially available products repel or kill ticks. Insect repellents containing the active ingredients DEET, IR3535, or picaridin can help prevent tick bites but they must be reapplied frequently. Products such as oil of lemon eucalyptus and citronella appear less effective.

DEET — The repellent that is most commonly used against ticks in the United States is DEET (N,N-diethyl-3-methylbenzamide). Products with 10 to 30 percent DEET are adequate in most cases. The higher the concentration of DEET in a product, the longer it lasts. It is important to read the label, so you know how much DEET is in the products you are using, and follow the manufacturer's instructions to determine how frequently to reapply.

It is important to talk with a health care provider about recommendations for using DEET on children. Used as directed, products that contain DEET appear to be safe for children older than two months of age. However, guidelines suggest products with more than 30 percent DEET should not be used on children.

Rarely, DEET can cause hives and blister-like lesions in some adults and children. There have also been occasional reports of neurologic reactions in small children exposed to excessive amounts of DEET; however, this appears to be very rare and limited to situations involving exposure to much more DEET than is present in most insect repellents.

Picaridin — Picaridin is another tick repellent that is available without a prescription in the United States and is available as a 7 or 15 percent solution. This agent has been successfully used for years as a tick repellent at even higher concentrations in Europe and Australia. The United States Centers for Disease Control and Prevention currently recommends picaridin as an alternative to DEET.

For prevention of tick bites, picaridin-containing repellents should be reapplied according to the manufacturer's instructions. No toxicity in humans has been reported, although liver toxicity has been reported in rats at very high doses. Unlike DEET, picaridin does not usually cause side effects. Picaridin is odorless, non-sticky, and non-greasy; it also does not irritate skin, stain fabrics, or degrade plastics.

IR3535 — IR3535 is another repellent, and it is available in many different products. As with all repellents, it should be reapplied according to the manufacturer's instructions. IR3535 may not be compatible with some synthetic materials.

Permethrin — Permethrin is a pesticide that kills ticks and mites. It can be applied to clothes, tents, and bed netting (but not directly to skin) and is effective in reducing the risk of tick bites. Permethrin does not appear to be harmful to humans, although it occasionally causes swelling and redness of the skin. Permethrin can be applied to clothing by mixing a premeasured amount of the product with water and immersing clothing in this solution for three to four hours and allowing it to dry. It can also be sprayed directly onto clothing and allowed to dry. Clothes with permethrin commercially embedded in the fabric are available and the tick-killing properties of permethrin can last through multiple (up to 60) washings when prepared commercially.

Inspect your clothes and skin — It is important to develop a habit of inspecting your skin (and a child's or significant other's skin) for ticks when coming in from the outdoors. This inspection should include areas where ticks most often bite, including the armpits, groin, backs of the knees, belt line, and the scalp. Showering or bathing may help you to detect ticks and wash off ticks that are not yet attached to your skin. Removing ticks within 36 hours makes transmission of the bacteria that causes Lyme disease very unlikely.

Placing clothes in a dryer — Placing dry clothing in a dryer for about four minutes after outdoor activities may kill ticks and reduce your risk of being exposed to ticks brought into the home.

CHANGES TO YOUR ENVIRONMENT — Making changes in the area where you live can reduce the chances of being exposed to ticks outdoors, although personal precautions are still essential after these changes are made.

●Install a tall fence — A tall fence that keeps deer (a carrier of ticks) out of the yard can reduce the number of ticks in an outdoor area.

●Cleaning forest borders and trimming lawns — Mice tend to live in areas that border forests. Cleaning these areas and laying down a 36-inch (approximately one meter) wide border of wood chips can decrease the number of ticks on a lawn. Keeping the lawn well-trimmed and improving exposure to the sun will discourage ticks from residing in grass.

●Treating residential property with tick-killing products — Treating one's property with products that kill ticks (eg, bifenthrin or permethrin) may reduce the local tick population; however, this approach has not been proven to reduce the number of new cases of tick-related diseases.

Strategies to reduce ticks on rodents have also been evaluated. These include bait boxes that treat white-footed mice (the most common carrier of Ixodes ticks) with tick-killing products or placing permethrin-soaked cotton balls in cardboard tubes outside for mice to use as nesting material; ticks feeding on these mice are killed by exposure to these products. However, studies have shown conflicting results on the effect of these measures on tick populations and one report found the use of bait boxes did not reduce tick-related diseases [1].

LYME DISEASE VACCINE — A vaccine was previously available to prevent infection with Borrelia burgdorferi. However, it is not currently available.

WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Lyme disease (The Basics)
Patient education: Insect bites and stings (The Basics)
Patient education: Rocky Mountain spotted fever (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: What to do after a tick bite to prevent Lyme disease (Beyond the Basics)
Patient education: Lyme disease symptoms and diagnosis (Beyond the Basics)
Patient education: Lyme disease treatment (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Clinical manifestations of Lyme disease in adults
Diagnosis of Lyme disease
Evaluation of a tick bite for possible Lyme disease
Lyme carditis
Epidemiology of Lyme disease
Musculoskeletal manifestations of Lyme disease
Prevention of Lyme disease
Treatment of Lyme disease
Prevention of arthropod and insect bites: Repellents and other measures

The following organizations also provide reliable health information.

●National Library of Medicine

     (www.nlm.nih.gov/medlineplus/lymedisease.html, available in Spanish)

●National Institute of Allergy and Infectious Diseases

     (https://www.niaid.nih.gov/diseases-conditions/lyme-disease)

●A review of Chronic Lyme Disease

     (https://www.niaid.nih.gov/diseases-conditions/chronic-lyme-disease)

●Center for Disease Control and Prevention

     (www.cdc.gov/ncidod/dvbid/lyme/)

●American Lyme Disease Foundation, Inc.

     (http://aldf.com/lyme-disease/, available in Spanish)

[2-7]