Head Lice. Written by Emily Skelton
About Head Lice
The head louse, or Pediculus humanus capitis, is a parasitic insect that can be found on the head, eyebrows, and eyelashes of people (CDC 2015). These parasitic insects live close to the human scalp and feed on human blood. An adult female louse is 2 to 3 mm long and can live up to 3 or 4 weeks, laying approximately 10 eggs a day (Frankowski, Leonard 2002). These eggs, called nits, are laid at the base of the hair shaft where they are firmly attached with a glue-like substance produced by the louse (Frankowski, Leonard 2002). Nits are very small and hard to see which allows them to be easily confused with dandruff or scabs. The eggs are incubated by body heat and after 10 to 14 days they hatch (Frankowski, Leonard 2002). Once the eggs hatch, a nymph emerges. A nymph looks like an adult head louse, but is smaller (CDC 2015). After 9-12 days of growing, nymphs mate and the females begin to lay eggs (Frankowski, Leonard 2002). The fully grown and developed head louse is about the size of a sesame seed, has six legs, and a tan to grayish-white color (CDC 2015). To survive, the louse injects small amounts of saliva and takes tiny amounts of blood from the scalp every few hours (Frankowski, Leonard 2002). An adult head lice can live about 30 days on a person’s head but will die within one or two days if it falls off (CDC 2015).
Signs and Symptoms
The most common symptom of head lice is an itchy irritation, which is caused by the saliva that the louse produces while feeding (Frankowski, Leonard 2002). Additional symptoms include a tickling feeling of something moving in the hair and sores on the head caused by scratching (CDC 2015). These sores can sometimes become infected with bacteria found on the person’s skin (CDC 2015). A person may also experience irritability and difficulty sleeping because head lice are most active in the dark (CDC 2015).
How does head lice spread?
Head lice cannot hop or fly; they move by crawling (Frankowski, Leonard 2002). The louse can crawl 6 to 30 cm per minute, making them difficult to find on the head (Frankowski, Leonard 2002). Direct contact with the hair of an infested person is the most common way to get head lice (CDC 2015). Head-to-head contact is common during play at school, at home, and elsewhere like camp (CDC 2015). Spread by contact with clothing or other personal items, such as combs or towels, used by an infested person is less common (CDC 2015). Animals do not play a role in the spread of head lice and personal hygiene and cleanliness in the home or school has nothing to do with getting head lice (CDC 2015). Head lice are not responsible for the spread of any disease, but instead cause high levels of anxiety among parents and school-aged children (Frankowski, Leonard 2002).
Lice in London
“Like the invading rats, plagues of immigrant bugs thrived in Londoners’ homes” (Velten 2013). Lice were among these bugs, having supposedly arrived from overseas into the docks (Velten 2013). People knew very little about lice in the 20th century, however the city of Westminster kept records of the number of cases of head lice for nearly 20 years. In 1921 there were 549 reported cases of head lice in children and 4 cases in adults (City of Westminster). In 1922 there were 619 reported cases in children and 4 cases in adults (City of Westminster). There were 864 reported cases of head lice in children and 13 cases in adults in 1923 (City of Westminster). The number of reported cases gradually increased until 1924, when there were 768 reported cases of head lice in children and 9 cases in adults (City of Westminster). In 1925 the number of reported cases rose again with 861 cases in children and an all time high of 117 cases in adults (City of Westminster). From here on out the number of cases began to steadily decline. There were 756 reported cases in children and 7 cases in adults in 1927 (City of Westminster). In 1931 there were 503 reported cases in children and zero in adults (City of Westminster). Lastly, in 1937 there were 558 reported cases of head lice in children and 3 cases in adults (City of Westminster). School children were sent to cleansing stations where they were treated and their clothes and bedding were disinfected. It was, and still is, not at all easy to find lice in girls’ heads because they often have much longer and thicker hair than boys (Edmonton). It was more difficult to diagnose and treat girls than it it was boys. Beginning in 1945, there was no evidence of an infestation of head lice (Kingston upon Thames). This was due to a considerable amount of work that was carried out to cleanse school children and family contacts (Kingston upon Thames). It was not found necessary to take any statutory action for infestation of head lice for the next 5 years (Kingston upon Thames).
Body Lice. Written by Lizzy Giroux
Although both feed on human blood, there are a few differences between body lice and head lice.
For one, unlike head or pubic lice, body lice live in the seams of clothing and on bedding, coming out of bedding to feed during the night or when it is dark (Gammon, 2016). In this way lice have mutually evolved specifically with humans seeing as humans are the only animals that wear clothing. We can also trace back to the first appearance of body lice in evolutionary history by looking at when humans first started wearing clothing. Because body lice have evolved living in the clothing seams of humans which is not as physically close to human skin, they are much more tough and durable than head lice and are therefore able to survive up to a week without human contact (Gammon, 2016).
Another big difference between the head lice and body lice is that while head lice are usually only a concern for hygiene, body lice pose a more serious health threat. This is because body lice can carry diseases like trench fever and lice-born typhus (Pittendrigh 2012). Pittendrigh also notes in an article in Insect Molecular Biology that even though head lice and body lice share so much genetic material that they are not to be confused with one another. Confusing the two could lead to panic because it would seem like if body lice and head lice are almost the same species then they must both be equally dangerous, and that simply isn’t the case.
Symptoms of Body Lice
The symptoms of body lice are very similar to head lice, but appear on any part of the body that may come in contact with clothing rather than on the scalp. Because body lice lay their eggs in the seams of clothing there are no visible eggs on the surface of the skin. However, body lice can be spotted by the unaided eye just like with head lice, and they leave the same irritating marks on the skin. Body lice bites are signified by red bumps on the skin, intense itching, and/or a rash caused by an allergic reaction to the bites (Healthline, 2015).
Body Lice in London between 1912 and 1952
Just like with head lice, the records of body lice for each city were kept by the medical officers of health in London. The original records do not give detailed descriptions on how body lice was found or what the symptoms were, but from the records it can be known how many people were treated for body lice, what was disinfected by the medical officers of health, and in what year and section of London they occurred within. In Westminster in 1923 all lice cases (including head lice and body lice) were treated at a public health station. While the infested people were being treated, their bedding was also removed for disinfection which came out to be 3,654 articles. Additionally, 26 children with body lice had 72 treatments. In 1924 in Westminster, 65 people in total were treated for body lice and 3 tons of old bedding were destroyed. In 1928 in Westminster 75 children under school age were given medicated baths for lice at a public disinfecting station, however there were no cases of body lice. Whether there were no body lice or they were simply overlooked is unknown. However, bedding and clothing were disinfected regardless which totaled to 937 articles. There were, however, 4 children of school age who were diagnosed and treated for body lice. Moving on from the area of Westminster, records were also kept of body lice in the city of Acton. In 1946 in Acton a total of 2 people were treated by use of baths for body lice. In 1948 a total of 3 people were treated for body lice. In 1949 only 1 person was treated for body lice. In 1950, 2 people were treated for body lice. In 1952, there were 6 people in total treated for body lice, which were discovered earlier in the year compared to 1946-1949. Finally, in the region of Edmonton the records are fewer, but more detailed than that of Westminster and Acton. In 1912 the number of children treated for body lice was 91, including 44 boys and 47 girls. The health officer also notes in this entry that the cleanliness of children had been steadily improving and that as the cleanliness of children improves, so does the standards of cleanliness that teachers hold to their students which, in turn, improves upon the overall well-being of the children of the region. Children from Edmonton who were found with body lice were immediately excused from school and were required to periodically visit the school nurse or be examined by a teacher (Edmonton 1912).
In conclusion, head lice are only an issue of hygiene while body lice pose a risk of lice-born typhus and trench fever. Little was known about lice in London in the early 20th century, but luckily the Medical Officers of Health kept extensive records of the number of people in each region who were found to have lice. These records have helped us to know how far we have come in eradicating the pest.
MOH Reports on Head Lice:
Secondary Sources on Head Lice:
Frankowski, Barbara L., Leonard B. Weiner, Committee On School Health, and Committee On Infectious Diseases. “Head Lice.” Pediatrics. September 01, 2002. Accessed April 06, 2017.
“Head Lice – Frequently Asked Questions (FAQs).” Centers for Disease Control and Prevention. September 01, 2015. Accessed April 07, 2017.
Velten, Hannah. “Chapter Seven. London Wildlife: The Persecuted and the Celebrated.” In Beastly London: A History of Animals in the City, 220-21. London: Reaktion Books, 2013.
MOH Reports on Body Lice:
Secondary Sources on Body Lice:
Gammon, Katharine. “Are Head and Body Lice the Same Species?” Inside Science. December 12, 2016. Accessed April 08, 2017.
Olds, B. P., Coates, B. S., Steele, L. D., Sun, W., Agunbiade, T. A., Yoon, K. S., Strycharz, J. P., Lee, S. H., Paige, K. N., Clark, J. M. and Pittendrigh, B. R. (2012), Comparison of the transcriptional profiles of head and body lice. Insect Molecular Biology, 21: 257–268.
Sullivan, Debra. “Body Lice Infestation.” Healthline. October 15, 2015. Accessed April 08, 2017.