If I had sensitivity to bites, I would treat my exposed skin with the more effective DEET. The EPA has approved permethrin treated clothes. The USA (and most other nation's) military, uses for uniforms and bug nets. So pretty well tested and approved worldwide. Yes, it is a dangerous poison, but not if you use as intended.
Permethrin used to kill bed bugs but overuse has gradually produced strains of bed bugs with pesticide resistance who are essentially immune to it. New types of pyrethroids will kill them better than permethrin but they are still pyrethroids just like permethrin and we're not sure how long they'll continue to be effective.
Permethrin is a pesticide that you spray on clothing to kill black flies, ticks, and mosquitoes but has no harmful side effects on humans if used properly. It is the active ingredient used in Insect Shield and Buzz Off clothing and kills bugs when they land on your clothing.
Factory-Treated Clothing to Repel Insects The only insect repellent currently used for factory treatment of clothing is permethrin. Permethrin is a broad spectrum, non-systemic, synthetic pyrethroid insecticide that targets adults and larvae of many species of biting, chewing, scaling, soil, and flying invertebrates.
Permethrin topical 1% kit : Apply lotion/creme rinse to shampooed and towel-dried hair until hair and scalp are saturated (especially behind the ears and on the nape of the neck). Leave on hair for 10 minutes and rinse with water. Use comb and/or gloves provided to remove remaining nits.
Applied to clothing, tents, outdoor furniture, or sleeping bags, Permethrin is very effective at reducing the mosquito population in your camping area and keeping ticks from attaching to you. Sawyer Permethrin uses the same active ingredient found in hair shampoos for head lice.