Variation in cutaneous perfusion due to synthetic pyrethroid exposure

Area of Science:

• Toxicology
• Dermatology
• Neuroscience

Background:

• Synthetic pyrethroids are neurotoxic insecticides with low mammalian toxicity.
• Previous studies indicate they are not skin irritants or sensitizers, with no apparent inflammation.
• However, skin exposure can cause paresthesia.

Purpose of the Study:

• To investigate the effect of topical synthetic pyrethroids on human skin's neurogenic vasodilatation.
• Specifically examining the impact of flucythrinate on skin responses.

Main Methods:

• Technical grade flucythrinate was applied topically to human forearms twice daily for five days.
• Laser Doppler velocimetry measured blood flow before applications.
• Histamine phosphate was injected intradermally to assess axon reflex vasodilatation.

Main Results:

• Laser Doppler velocimetry showed no statistically significant changes in blood flow.
• Histamine-induced axon reflex vasodilatation was not statistically significant (alpha = 0.05).

Conclusions:

• Topical exposure to synthetic pyrethroids, such as flucythrinate, appears to have minimal influence on neurogenic vasodilatation in human skin.
• The findings support the notion that these compounds do not elicit significant inflammatory or vascular responses upon skin contact.