How Effective Is Permethrin-Treated Clothing in Preventing Tick Bites?
Permethrin-treated clothing can reduce tick contact, but effectiveness declines with wear and washing.
A study by Connally and colleagues examined how wearing and repeated washing affect the ability of permethrin-treated clothing to repel and kill Ixodes scapularis nymphs.
Investigators exposed ticks to treated clothing for 30 to 120 seconds and then monitored their movement on both treated and untreated fabrics.
Effectiveness Before Washing
“Pristine permethrin-treated clothing displayed strong contact irritancy and toxicity toward I. scapularis nymphs,” writes Connally.
After one hour of contact, only 0–30% of ticks showed normal movement, indicating strong impairment or death.
Impact of Washing and Wear
After 16 days of wear and 16 wash/dry cycles, permethrin levels dropped by 50–90%.
This reduction was associated with decreased effectiveness. After exposure to washed clothing, 31–67% of ticks displayed normal movement.
Despite this decline, treated clothing still performed better than untreated garments, where 90–100% of ticks remained fully active.
Socks and Shoes: Variable Protection
Permethrin-treated socks had a less pronounced effect, possibly due to fabric structure allowing reduced contact with the insecticide.
Treated shoes, which were worn but not washed, retained stronger tick-killing activity.
Important Limitations
This study has several limitations. Ticks in real-world conditions may attach in less than 30 seconds, reducing exposure time to treated fabrics.
Ticks that reach exposed skin directly may not be affected by treated clothing.
The study also did not address potential safety concerns some individuals raise regarding permethrin exposure.
Clinical Takeaway
Permethrin-treated clothing helps reduce tick exposure, but effectiveness decreases with repeated washing.
Related Articles:
References:
- Prose R, Breuner NE, Johnson TL, Eisen RJ, Eisen L. Contact Irritancy and Toxicity of Permethrin-Treated Clothing for Ixodes scapularis. J Med Entomol. 2018.
- Connally NP, Rose DA, Breuner NE, et al. Impact of Wearing and Washing of Permethrin-Treated Clothing. J Med Entomol. 2018.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
I live in SE Pa, my dear daughter has had Lyme disease with bullseye rash and other symptoms twice, and once with Neuroborreliosis symptoms and highly positive 2 tier serology and Western blot for IgM and IgG. She has never recovered fully from her 3rd bout. I urge everyone in highly endemic areas like mine to wear permethrin treated clothing, though it may not work 100% and though I, too, do not like the idea of wearing pesticides- the alternative of Lyme or other tick-borne disease is worse. I watched a deer tick struggle and die on my permethrin treated socks while gardening and it was very satisfying.