Updated June 23, 2021
Thirty-five years have passed, but I have a vivid memory of the day I learned one of my kids had lice. I was horrified as I watched my four-year-old keep scratching his scalp through a thick mop of hair and took a good look. Yikes! Not knowing any better, I took a neighbor’s advice and rushed to the drugstore to get the most “effective” brand I could find to treat it. Effective probably meant the most toxic. I later learned the source, but that didn’t reduce my gut reaction.
Reportedly, 99% of the lice in the United States are resistant to pyrethrins and permethrins, chemicals used in many lice-fighting brands. Further, Lindane, used in Kwell shampoo for lice, is a highly toxic pesticide related to the banned DDT. Cancer-causing, it can also damage the liver, immune system, and nervous system, even triggering seizures in sensitive people.
WARNING! Lindane shampoo is often recommended when the first line of treatment was not successful. The company warns that it should be used “with caution in infants, children, the elderly, and individuals with other skin conditions, and those who weigh < 110 lbs (50 kg) as they may be at risk of serious neurotoxicity. “