Pediculicides
Medications used to treat lice are called pediculicides. Available products may contain permethrins or pyrethins (pyrethroids). These substances are insecticides derived from chrysanthemum flowers. Permethrin 1 percent is a synthetic pyrethroid whereas pyrethrins is organic; therefore, sensitivity is possible for those children allergic to chrysanthemum or ragweed. Lindane and malathion are two other insecticides used as secondary treatment options because malathion is highly flammable, and lindane has been shown to cause serious and sometimes fatal side effects in young children.
According to the Coalition for Alternatives to Pesticides, these insecticides are mixed with other substances like methyl paraben, which is a skin sensitizer. The addition of such chemicals has a synergistic effect on the insecticides, making them more potent and more easily absorbed by the body. This is significant because children have a greater body surface area and when the pediculicides are applied to multiple areas like the head and torso, greater amounts of the pediculicide are absorbed. The Food and Drug Administration (FDA) warns against using these products, particularly lindane, on premature infants because their skin is more permeable, allowing for greater pediculicide absorption.
Neurotoxic
According to the Pesticide Action Network, pediculicides are neurotoxic. Frequently, these pediculicides inhibit the effects of cholinesterase in the body. Cholinesterase is an enzyme needed for smooth transmission of nerve impulses. Toxicity from cholinesterase-inhibiting pediculicides causes weakness, nausea, tremors, paralysis and possibly death. Other neurotransmitters are also affected, which is why children who are sensitive to the pediculicide, or who receive a large quantity of the chemical, may experience hyperactivity, elevated temperature, lack of coordination, seizures and altered respiratory function.
Carcinogen
According to the U.S. Environmental Protection Agency, insecticides like permethrins and lindane, and additive ingredients such as hexachlorocyclohexane (HCH), have been found to affect intercellular communication, causing abnormal cell growth. This can lead to cancer cell development.
Increased Risk
According to the FDA, healthy infants and children and children with metabolic disorders are at greater risk of experiencing neurotoxicity and complications from pediculicide use. Children with sulfate-related enzyme disorders cannot properly break down permethrin so use should be restricted to avoid neurotoxicity. The liver plays an important role in metabolizing pediculicides so children with altered liver function should not use these products unless under the direct supervision of a physician.
