The ABC approach to bedbugs for the first contact clinician
A bed bug infestation can leave your patients feeling lousy. This 5-minute blog will give you the tools to help your patients scratch that itch for good.
What are bed bugs?
Bed bugs are small brown insects (Cimex hemipterus or Cimex letularius) that feed on human blood. It only takes a handful to infest a new location, creating a vast colony. The bites are painless but cause a local immune reaction, leading to itchy lesions.
Bed bugs carry up to 45 known pathogens, including hepatitis C and the bacteria responsible for trench fever. Fortunately, no transmission has been recorded from bedbugs to humans.
Bedbugs live around 4-5 months and can live up to 70 days without a meal. They sense their prey by detecting expired CO2 from your breath.
What does a bedbug look like?
Only around 10% of patients can identify the bugs by sight.
Bedbugs are not uncommon in overcrowded urban environments. Families in overcrowded temporary accommodations are likelier to present with bites than those from more affluent households. Also, ask about recent travel to warmer climates – particularly if they have been staying in hostels or overcrowded environments.
Here are a few tips on recognising bedbug infestation.
Appearance
Small, brown, fat and round – bed bugs have a distinctive appearance. They also litter the environment with a few other clues to their presence.
They leave casts of their exoskeletons from shedding during growth. These look like the bugs themselves. Sometimes, they also leave little black dots on the bedsheets. These black dots are bedbug poop and can be a vital clue.
Bedbugs and scabies are easily confused. The scabies mite, Sarcoptes scabei, burrows into the skin, causing an intense itch. This itch is due to a reaction to scabies poop.
Bites
Bedbugs produce small, discrete clusters of bites that can occur in a zig-zag pattern (known as the breakfast, lunch and dinner pattern).
These bites are maculopapular, red, and itchy. They appear in the morning, after waking up, and get itchier throughout the day. They can take a few days to appear.
They are more likely to occur in exposed areas, such as body parts not covered by bedsheets. The symptoms are self-limiting but can last a couple of weeks.
Catch them
You can buy scented traps to catch the bed bugs. These will release CO2, or other chemicals, to attract them. This can help detect even mild infestations, but this does nothing to reduce the population.
Because bedbugs release a very sweet scent, dogs can be trained to sniff them out and have been used by the cruise line industry to prevent infestations. Sounds great, but sadly, dogs are unreliable in real-world conditions.
What problems do bedbugs cause?
Bedbug bites are self-limiting and minor. They are irritating, but what harm do they actually do? The main risks are due to the secondary effects of the bites rather than the bite itself.
They include the following:
Anaphylaxis
As with any bite, bedbug salivary proteins will be transferred into the prey. Proteins are thought to cause the immune reaction we normally see with these bites. They can also cause more severe, systemic reactions such as anaphylaxis. This is naturally an emergency and should probably be managed before reading the rest of this post.
Bacterial infection
The bites usually heal well if left alone. Unfortunately, the bites are intensely itchy, meaning they are likely to be scratched. This can lead to a secondary infection caused by skin commensals. We should treat this cellulitis with antibiotics. Flucloxacillin is a good choice as there is excellent skin penetration. It also provides good cover for skin flora, the likely cause of the infection.
Cognitive effects
Being a victim of an infestation carries its own psychological stress. Patients can also feel a significant stigma attached to having an infestation in their homes. On top of this, the incessant itching can significantly disrupt sleep. This disruption of sleep can have a significant effect on your patient’s mental health.
How do you get rid of bedbugs?
We support our patients in ridding their homes of these bed bugs. Exterminators may be needed to rid homes of infestations entirely. They have access to chemical and heating methods to help rid homes of bugs. But the following strategies may also help reduce the parasite population living with your patients.
Apply heat
Bedbugs don’t survive below -20 °C or above 60 °C. Your families should wash all the bedsheets at a high temperature. This can eliminate any of the adult bedbugs as well as any eggs. Commercially available steamers reduce population numbers quickly and drastically.
Bag them up
Using a vacuum cleaner with a removal bag can reduce the population size. Your patients won’t get every bug, but repeatedly doing this will drastically reduce population sizes. The bags should be immediately removed and sealed in plastic after use.
Chemical control
Anti-parasitic drugs such as ivermectin can reduce the population of bugs feeding on humans. Sheele et al. showed that this effect could be detected in insects fed on human blood up to 96 hours after the dose. It was a small sample size, so it is a weak recommendation. However, it is a promising start.
Unfortunately, bedbugs have developed resistance to DDT, organophosphates, carbamates and pyrethroids. Permethrin will likely have little effect.
Take Home Points
Appearance
Our patients will be poor at recognising bedbugs. Help them identify the creatures and look out for the signs.
By-Products
Bedbug bites are irritating but not deadly. Be on the lookout for the secondary risks of allergy, infection and stigma.
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Control
Washing sheets and hoovering may reduce populations, but often exterminators are required to eradicate an infestation completely.
References
BéRenger J-M, Almeras L, Leulmi H, Parola P. A high-performance vacuum cleaner for bed bug sampling: a useful tool for medical entomology. Journal of Medical Entomology. 2015;52(3):513-5.
Committee PF. BNF for Children (online) London: BMJ Group: Pharmaceutical Press, and RCPCH Publications; 2022 [Available from: http://www.medicinescomplete.com.
Cooper R, Wang C, Singh N. Accuracy of Trained Canines for Detecting Bed Bugs (Hemiptera: Cimicidae). Journal of Economic Entomology. 2014;107(6):2171-81.
Donahue WA, Showler AT, Donahue MW, Vinson BW, Hui L, Osbrink WLA. Knockdown and lethal effects of eight commercial nonconventional and two pyrethroid insecticides against moderately permethrin-resistant adult bed bugs, Cimex lectularius (L.)(Hemiptera: Cimicidae). Biopest Int. 2015;11:108-17.
Goddard J, deshazo R. Bed bugs (Cimex lectularius) and clinical consequences of their bites. Jama. 2009;301(13):1358-66.
Ogbuefi N, Kenner-Bell B. Common pediatric infestations: update on diagnosis and treatment of scabies, head lice, and bed bugs. Current Opinion in Pediatrics. 2021;33(4).
Parola P, Izri A. Bedbugs. New England Journal of Medicine. 2020;382(23):2230-7.
Reinhardt K, Harder A, Holland S, Hooper J, Leake-Lyall C. Who knows the bed bug? Knowledge of adult bed bug appearance increases with people’s age in three counties of Great Britain. Journal of medical entomology. 2008;45(5):956-8.
Sheele JM, Ridge G, Li X, Schlatzer D, Lesser E. The benefit of a single oral dose of ivermectin in humans: the adverse effects on Cimex lectularius L. populations and fecundity. Cureus. 2019;11(11).
Wang C, Singh N, Zha C, Cooper R. Bed bugs: Prevalence in low-income communities, resident’s reactions, and implementation of a low-cost inspection protocol. Journal of medical entomology. 2016;53(3):639-46.
Wang D, Wang C, Wang G, Zha C, Eiden AL, Cooper R. Efficacy of three different steamers for control of bed bugs (Cimex lectularius L.). Pest management science. 2018;74(9):2030-7.
