Why Heated Air Over Prescribed Lice Treatments?

If your dermatologist prescribed permethrin, you may be wondering, “Why would I choose a heated-air treatment instead?” Permethrin, for example, is a commonly used treatment for head lice, but resistance to pyrethroid insecticides is an increasing concern.

A 2023 study found that more than half of the head lice studied showed resistance to pyrethroid insecticides, the class of insecticides that includes permethrin. Researchers found that permethrin had particularly high levels of resistance, and resistance appeared to become more common over time (Abbasi et al. 2023). Based on these findings, the researchers recommended considering alternative treatments when resistance to these insecticides is high.

Resistance isn’t the only concern with permethrin. It also needs to be applied properly according to the treatment instructions to work effectively. Because permethrin primarily targets live lice, a second treatment is needed to kill newly hatched lice. It can also cause scalp irritation, itching, redness, or a burning sensation in some people. Furthermore, the topicals are ineffective in killing the lice eggs and extracting the eggs is a difficult task.

This is where heated-air treatment offers a different approach. Unlike permethrin, heated-air treatment does not rely on an insecticide to kill lice. Instead, it uses controlled warm air to dehydrate and kill lice and their eggs. Because it does not depend on the lice being susceptible to pyrethroid insecticides, it offers an alternative approach when insecticide resistance is a concern. It also avoids repeatedly exposing the scalp to an insecticide when a non-insecticidal option is available.