Head lice are small insects that feed on the blood from the human scalp. An infestation of head lice is called pediculosis capitis, and it mostly affects children. It is spread by direct contact with the hair of someone who has head lice. Treatment for head lice will typically focus on killing the lice and their eggs as soon as possible to prevent them from returning or multiplying.
Most of the time, a head lice infestation can be treated with over the counter medications that will kill the lice and their eggs. However, the first treatment usually will not kill any of the recently laid eggs, so an appropriately timed second treatment is necessary in order to completely get rid of the infestation. Your doctor will likely recommend a treatment schedule to help you keep track of things.
Over-the-counter products for head lice come from the chemical compound pyrethrin, which is extracted from the chrysanthemum flower and is toxic to lice. The hair will need to be shampooed beforehand, but do not use conditioner. Also, rinsing the hair with white vinegar might help dissolve the glue that holds the nits to the hair strands. The common OTC medications include:
- Pyrethrin with additives (includes Rid and A-200 Lice Killing): In these medications, pyrethrin is combined with other chemicals that enhance its toxicity.
- Permethrin (includes Nix): This is a synthetic version of pyrethrin.
For both of these types of medications, the side effects can include itching and redness of the scalp. If you or your child is allergic to chrysanthemum or ragweed, consult your doctor before use.
In places where lice are more common, they are sometimes able to develop a resistance to over-the-counter medications. Additionally, sometimes this method can fail if it is not used correctly. If either of these scenarios is true for you, your doctor might prescribe a prescription medication. Common prescription treatments for head lice include:
- Ulesfia (benzyl alcohol): This medication works by depriving the lice of their oxygen and ultimately suffocating them. This method of treatment is not approved for children less than six months old because using benzyl alcohol to clean medical equipment has been shown to cause seizures in newborn infants. Side effects for this medication might include redness or itching of the scalp.
- Ovide (malathion): This medication is typically recommended for children who are six years or older. It is a medicated shampoo that is applied and left to dry naturally before being rinsed out eight to twelve hours later. However, since this medication is very high in alcohol content, it cannot be used near a hair dryer or open flame.
- Lindane: This type of medicated shampoo is typically only used as a last resort when all other treatments have failed. This is because the product comes with the risk of severe side effects, including seizures. For this reason, Lindane is not recommended for use on children at all.