Posted on: 20 April 2015
Pediculosis and scabies are two common medical conditions, and both are caused by parasitic organisms. The head louse (Pediculus humanus capitis), a tiny wingless insect, is responsible for pediculosis, better known as head lice; the even smaller itch mite (Sarcoptes scabiei), is the culprit in the case of the skin disease scabies. While significant medical complications from each condition are rare, both conditions cause annoying itching and are a source for embarrassment. Treatment at home can be difficult, but dermatologists have an arsenal of effective, powerful medications at their disposal. Below are some prescription treatments for head lice and scabies, along with information about their use and precautions to take while using them:
Used as a commercial pesticide in agriculture, permethrin is a neurotoxin that is lethal to insects and other small invertebrates. It is available as a low-concentration formula as an over-the-counter treatment for head lice. However, its most prominent use is for the treatment of scabies, and it is available by prescription-only for that purpose.
To treat scabies, permethrin cream is applied to the entire body and allowed to remain for several hours; typically, permethrin will kill all mites and their eggs in one application. Permethrin has been proven safe for human usage at ordinary dose levels; however, the precautions below should be taken while using it:
- Keep permethrin away from fish and cats – both aquatic wildlife and house cats are vulnerable to permethrin, and both are likely to die as a result of contact with the medication.
- Permethrin may cause minor skin irritation – some skin irritation while using permethrin is not unexpected, but severe reactions involving hives, difficulty breathing or swelling should be addressed as medical emergencies.
Another pesticide, malathion has a successful history of treating a variety of pests including fruit flies and mosquitoes. However, it also is a highly-effective prescription treatment for pediculosis and scabies. Malathion is available as a lotion that is rubbed into the hair or on the body. It is considered safe for humans, but there are a couple of precautions involved in its use:
- Ingestion of malathion can be serious – inside the human body, malathion is changed by metabolic processes to malaoxon, a toxic substance capable of causing systemic illness. Do not apply malathion near the mouth, nasal passages or eyes.
- Malathion is flammable – malathion can be readily-ignited by a flame or source of heat; never smoke while using malathion and be cautious when in the presence of stoves, heaters and other possible igniters.
Benzyl alcohol is found inside a variety of organic products, including tea and various oils. It is useful in treating head lice when prescribed by a doctor, and it poses no known dangers to humans if used properly. However, keep in mind the following precautions when using benzyl alcohol:
- Benzyl alcohol can cause blindness – never allow benzyl alcohol to enter your eyes. If it does make contact with your eyes, flush them in water and obtain immediate medical help.
- Do not use benzyl alcohol with children younger than six months – benzyl alcohol has a connection to severe respiratory distress in infants, and exposure could prove to be fatal.
Lindane is a formerly-widespread pesticide, but its use has declined in recent decades due to environmental toxicity. It is still sometimes prescribed for the treatment of head lice and scabies if other medications are not fully-effective; however, its use is limited due to its potential to cause negative reactions and for its unknown long-term effects on the human body. If you are prescribed lindane, the doctor has a good reason for doing so, but be sure you adhere to the directions completely before taking it. Below are precautions that should be taken when using lindane:
- Lindane is not safe for children and others of small stature – lindane's use should be limited to those who weigh well over one hundred pounds.
- Be prepared to respond to adverse reactions – if you use lindane, be ready to handle any possible reaction to the medication, including seizures and severe skin irritation. Get medical assistance immediately if such a reaction should occur.