Diseases & Conditions

Head lice infestation

Head lice infestationCausesMedicationsPreventionRisk FactorsSymptomsTreatment


Pediculues humanus capitis - the head louse is the insect that is responsible for the medical condition normally known as head lice infestation. This insect is a hematophage i.e. it uses the blood of the host as food for survival. The head louse can occur in any part of the body with hair, typically in the head where it is densest. The presence of the insect is characterized by constant itching caused by the bites of the lice on the skin. Treatment normally involves application of insecticides such as Pyrethrin or Permethrin to the affected areas. But many regional and traditional remedies are also available for treating head lice infestation.


The causative agent for the head lice infestation is the adult head louse that feeds on blood and is present in the hair and scalp of the infected persons.


There are many medications that are available in the market for treatment of head lice infestation. Most of them are shampoos that use a particular chemical that has been known to be effective against lice.

Lindane is one of the popular shampoos and has been a prescription drug for head lice for a longtime. The shampoo is highly toxic and accidental ingestion of the shampoo orally is highly dangerous. As the chemical in the shampoo is known to cause damage to the nervous system single application is recommended by most physicians.

Malathion is a prescription drug that is a combination of different drugs both natural and manmade. Combined with iso-propyl alcohol ad a naturally occurring tea tree oil extract terpineol malathion is considered safe when used as per the instructions of the physician.


Regular checks of the hair for lice are one of the best ways to identify the start of a Hematophage infestation. Early diagnosis makes it easier to treat and reduces the possibility of the condition spreading to others. Clothes and combs used by a person having an infestation should be treated with care and should be exposed to sun light or rinsed in water at around 60 degree Celsius to ensure the destruction of all the remaining lice.


As an insect is the root cause of this condition, direct or indirect physical contact is the main method of propagation. If a person comes in direct physical contact with a person who is suffering from head lice infestation or if the person uses the clothing, blankets or bed the possibility of contracting the condition is very high. Children are more prone to the condition as they often share and use items at school and play areas with a higher frequency than adults. Girls are affected more due to the presence of higher amount of hair in the scalp region for the women.


Hematophage Infestation is characterized by the constant itching feeling in the scalp region which is caused by the bites of the head louse as they break the skin to get access to the blood underneath the skin. The human body has an allergic reaction to these bites and the result is the itching sensation.

If the itching is very prevalent then sores might appear from constant scratching. These sores can become infected if proper care is not taken and irritability sets in.


The treatment for Hematophage Infestation should involve a complete destruction of the head lice and the eggs that are there buried in the scalp of a person. As there are no single method that would assure such results in a single treatment cycle it is best to go for an effective multi stage treatment program which will involve various degrees of success. These methods may involve chemical treatments or naturally occurring remedies that are friendlier to the hair follicles in the long run.

Physical removal will involve the use of knit combs that can sieve out lice large enough to get caught in the comb when run through the hair. One can also use disinfectants and high heat laundering to get rid of the eggs and head lice that might have gotten into clothes. As the human body is the area from which the infestation starts, utmost care should be given to personal hygiene. Over time many of the head lice have become resistant to usual chemical treatments and can withstand repeated treatments. Increasing the toxicity of the treatments or the harshness of the chemicals can lead to hair loss and skin irritation.

Constant treatment for lice is not effective as we eggs in the hair and skin can survive chemicals that might kill the live mice. So, periodic checks for live lice and corresponding treatment are the best way to keep the problem under control.