As I walk into the classroom to pick up my young child from school, I am greeted with a battlefield of zombie-like bodies strewn across the colorful carpet. I quickly scoop my son up off the floor, but my heart begins to race, thinking about that communal carpet, and I can’t help worrying about the possibility of head lice…
Should I keep my child home forever?!
There is a lot of stigma attached to the diagnosis of head lice, so with this in mind, let’s break down some of the common myths surrounding the diagnosis, spread, and prevention of this pesky parasite so we can better inform our patients, our schools and maybe most importantly, ourselves.
The basics: What are head lice?
A head louse is a parasitic insect commonly found on an infected human’s hair (scalp, eyebrows, and eyelashes) and feeds off the host’s blood. Head lice exist in three stages: the egg (also called a nit), the nymph, and the adult. A female louse lays its nits at the base of the scalp. These small (think the size of a knot in a thread) yellow or white oval-shaped eggs take about nine days to hatch. Upon hatching, a nymph will mature into an adult louse in about nine days. The nymphs may be hard to identify on direct visualization. The adult louse is approximately the size of a sesame seed and is typically a tan-ish, white-ish, or grayish color. It can live for about 30 days and stays firmly attached to the hair near the skin so that it can feed several times daily. They are typically visible to the naked eye.
How are lice spread, and more importantly, NOT spread?
We all know lice are most commonly spread by close person-to-person contact, but what does that actually mean? Studies show that direct and prolonged head-to-head contact is the most likely mode of transmission. Specific examples include bed-sharing with household contacts and close play at school or in sports.
Understanding this simple point is crucial as there are many myths and unfounded fears about how this pest can spread. Remember, lice move by crawling. They cannot fly or jump and are actually quite happy to stay where they are once anchored on a host.
A louse will typically leave a host only in cases of heavy infestation where prime feeding real estate is limited. Transmission through objects like clothing, hair brushes, and even classroom carpets is uncommon. One study showed that the lice found on hair brushes were likely dead or injured, and only 4% of pillowcases used by infected patients had live lice on them. For those louse that do abandon ship, it is reassuring to know that if not actively feeding on a host, a stray adult louse will die within one to two days, and a nymph can only survive just a few hours. Moreover, if you were worried about coming into contact with a nit-laden strand of hair on a fomite, you will be reassured to know that a nit becomes unviable very quickly if placed in an environment where its temperature is not close to that of its host. Another common fallacy is that pets can play a role in the transmission of lice – they don’t; this is only a disease of humans.
So, how can we use this information practically in the real world?
For one, in the office, when evaluating a patient with an active head lice infestation, be aware that it is extremely uncommon that you will catch lice from this patient. General safety precautions like gloves, a simple gown, and a hair net should suffice, but even gloves alone are most likely fine. The hazmat suit is unnecessary; remember, lice don’t jump! Patients will feel the stigma and shame associated with this diagnosis, and the last thing they will need is to be further embarrassed by unnecessary judgment from their clinician or staff- we can do better.
I know what you are thinking though; what about after they leave the room? Does the room have to be shut down for the day, fully renovated, and then deep cleaned before its next use? Another empowering piece of information to educate your patient and office staff with is that you do NOT have to go crazy with both time and money-intensive cleaning protocols to avoid reinfestation. As we learned above, it is very unlikely to infest someone with lice or nits that have fallen off the head or crawled onto furniture or clothing. Not impossible, but very unlikely. This is why some very directed communication on proper cleaning techniques can be game changers.
For starters, a simple vacuuming of the floor or furniture the infested person was using should take care of any stray lice or hairs with viable nits attached. No expensive house tenting or ancillary services are needed. Next, hot water is king when it comes to destroying this pest. Both lice and eggs are killed by exposure to temperatures greater than 128.3 F for at least five minutes. Most literature recommends machine washing and drying all clothing and bed linens used by the infected person within the last two days before medicinal treatment by using the hot water setting (130 F) and a high heat drying cycle. Objects like toys, combs, or brushes can be soaked in hot water for at least five to ten minutes. For non-washable items, it is recommended to seal them in a plastic bag for two weeks before use.
It is so important to reassure the patient and family that personal hygiene or cleanliness in the home or school has NOTHING to do with getting head lice. They will be stressed thinking their entire family will get lice and that they did something wrong. Education and empathy here are paramount. Simple pearls like avoiding sharing common household objects, reducing activities that lessen the risk of head-to-head contact (like bed sharing), and empirically treating close contacts will all aid in avoiding spread and re-infestation. Empowered with the information discussed today, we can provide really good guidance and care for managing lice.
