With rates of tick-borne illnesses on the rise, it may be worth investing in clothing treated with the insecticide permethrin if you spend time in areas where ticks roam. Such garments can prevent bites by several species of ticks that cause Lyme disease and related conditions, according to recent tests by the CDC.
Permethrin is a synthetic insecticide similar to a natural chemical in chrysanthemums. Earlier research by the CDC found that permethrin-treated garments kill Ixodes scapularis (known as the deer tick, blacklegged tick, or bear tick), which spreads Lyme disease.
In the latest study, a CDC team purchased various permethrin-treated garments (including a shirt, pants, and socks) from a maker of insect-repellent clothes and tested them against the blacklegged tick as well as two others: the lone star tick and the American dog tick. They found that exposing the ticks to the garments for as little as one or two minutes caused most of the bugs to become sluggish and unable to bite within an hour; an exposure of five minutes effectively disabled all the ticks tested. By comparison, placing ticks on an untreated cotton T-shirt had no effect.
Permethrin-treated clothing is sold under brand names including Insect Shield (used in the CDC study) and BugsAway. Of course, it's also effective, not to mention cheaper, to buy permethrin spray and treat your own clothes. (Make sure to buy a product intended for use on clothing, not agricultural use.) If you do spray, always follow the label instructions and take steps to avoid getting it on your skin or inhaling it. Permethrin should never be applied to skin, only to clothing or gear. If exposures occur, be sure to follow the first aid instructions on the product label carefully. Note that self-treated items will need 24 to 48 hours to dry before you wear them.
Whichever method you choose, checking your skin for ticks after venturing outdoors is still essential. And it’s still a good idea to follow other steps for preventing tick bites, such as applying topical repellents to exposed skin and wearing long sleeves and long pants (tucked into your socks or boots) when out in the woods or tall grass.
A version of this article first appeared in the UC Berkeley 2019 Arthritis White Paper.
Also see Summer Bugs That Can Bite You.