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Was I overexposed using DEET under clothes?

En español

Travis was vacationing in California for three weeks. During that period, he noticed the mosquitoes were aggressive and continuously swarming around him. He became increasingly concerned about contracting a disease carried by mosquitoes.

Travis decided to purchase an insect repellent product (a pesticide that repels pests) containing DEET. He sprayed the repellent on himself daily, and often reapplied every two or three hours. On a number of occasions, Travis covered his arms and legs with the product, and then, put on his shirt and pair of pants.

After two weeks of using the repellent in this way, he noticed his skin was beginning to tingle and itch. Towards the end of his vacation, sores and blisters were appearing on his arms and legs.

When Travis returned home, he wondered if his skin reactions were related to his repellent use. He found NPIC's website and decided to call them.

NPIC's Choosing and Using Insect Repellants web page has health related information on repellents, including:

  • Information on choosing and using a repellent,
  • Comparative effectiveness of DEET and other active ingredients,
  • Fact sheets on DEET and other active ingredients in repellents, and
  • Use and safety of DEET for children and pregnant and nursing women and when combined with sunscreen.

Take Home Message

Travis learned from the NPIC Specialist that repeated misapplications and prolonged exposures to a DEET repellent could potentially cause the skin to tingle, flake, and feel irritated. In some cases, overexposures have caused dermatitis and worsened pre-existing skin diseases.

The NPIC Specialist explained to Travis that while the repellent can be applied on his bare skin and on top of clothes, it was not to be applied under them.

Furthermore, the instructions stated to "avoid over-applications of the product" and that it provided "up to 6 hours of protection." In order to prevent prolonged exposures, the label indicates to "wash treated skin with soap and water after returning indoors."

Travis admitted he did not read the entire label on the product. The NPIC Specialist explained the importance of reading the label directions and following them carefully for each application, because they contain valuable information on how to properly use products.

Travis learned if he had followed the label directions, harmful effects would not have been expected. Since Travis was interested in learning more about how to safely use repellents, the Specialist lead him to Environmental Protection Agency (EPA) and Centers of Disease Control and Prevention (CDC) websites for additional information.

The Specialist provided Travis the phone number to his Poison Control Center so he could access medical treatment information for his symptoms.