Treating hair lice in difficult hair

Theory

Hair lice are a relatively innocent parasite that lives in human head hair. Although they are typically not disease carriers, the itching can be extremely frustrating.

Hair lice attach themselves by holding onto the hair, typically close to the skin of the head, which they need to do actively, ie. they need to be alive to do so. Dead hair lice will eventually fall out.

Typical recommendations revolve around using substances that are in some way deadly to lice; depending on substance, by poisoning them, dehydrating, or both. These substances are used along with a lice comb, which is a comb with very fine teeth (with just enough space between teeth for strands of hair to pass through), and essentially 'pulls' the weakened lice out of the hair.

Unfortunately this approach doesn't work for everybody; if you have long or particularly tangle-prone hair, it can be nearly impossible to get down to every bit of skin on your head. Given that the treatment needs to be repeated daily, and missing even one louse can make your efforts futile, this can make it impractical.

Heat treatment

There are experimental heat treatment techniques to remove hair lice; these involve purpose-built devices for removing lice by dehydrating them, causing them to die and lose grip. Heat travels through tangled hair much more easily than a comb, and so can have a higher success rate. Unfortunately, you are unlikely to have such a specialized device at home, and it can be difficult to find someone to do it for you, especially if traveling is difficult or you do not have a lot of money to spend.

Fortunately, however, this process can be replicated with a simple hairdryer, as long as you are careful. Make sure your hairdryer is set to 'hot' mode, and your hair is dry. Then blow hot air through your hair, close to your head, for at least several minutes daily, for the usual treatment period of two weeks.

You need to be very careful when using hot air this close to your head. It's okay for your head to start feeling hot, but as soon as you start getting a burning or scorched feeling on the top of your head, stop the treatment immediately, and keep more distance the next day. If you do not have a lot of hair, you may need to keep the hairdryer at quite some distance - thickness of the hair affects what the correct distance is for you.

A method that I've found particularly effective is to blow air upwards; that is, instead of blowing onto your hair from the top, point the hairdryer upwards and blow it under your mop of hair, as it were - it should feel a bit weird, causing your hair to go in all directions. This maximizes airflow, as the air somewhat gets trapped under your hair, and the only way out is through; this minimizes the deflection of air you would get when blowing from the top down. Note that the upwards technique can worsen hair tangling.

You may also want to use a lice comb in the places where this is easily possible to do; it is not strictly required for the treatment to work, but it makes it easier to clear out the dead lice in one go, instead of having them fall out by themselves over time.

Make sure you continue for the full two weeks, with daily treatment; hair lice have a short breeding cycle, and this treatment only affects the living lice, not their eggs. This means that over the span of two weeks, you will need to gradually dehydrate every new generation of lice. Doing it daily without fail ensures that no generation has a chance to lay new eggs. If you miss a day, you may need to restart the two week timer.