(edited from the skintherapyletter.com article: Bedbugs: An Update on Recognition and Management)
The common bed bug, (Cimex lectularius) has been a pest to mankind for centuries. Over the years bed bug populations in industrial nations declined steadily with the advent of pesticides, improved sanitation practices, and economic conditions.1 However, pest control companies in Canada and the United States are reporting overwhelming increases in the number of new bed bug encounters compared with 10 years ago.3
This recent resurgence of bed bugs has been attributed to the species developing resistance to pesticides, along with increased rates of international trade and travel, as travelers can unknowingly bring the insects home with them in their clothing and luggage.4,5 Which in turn, can spread the problem to other areas at an exponential rate.
In addition to inflicting itchy and uncomfortable bites, bed bugs may also pose serious health concerns. Research has shown that bed bug bites can potentially spread bacterial infections and diseases such a Hepatitis B.
This article will review the lifecycle/feeding patterns of bed bugs, treatment options for bites, disease transmission, the social impact of infestations and tips for getting rid of them.
How to Spot a Bed Bug
Bed bugs are broad, oval-shaped, flat, wingless insects.14 Adults are red-brown in color and typically measure 4-7 mm; they are often compared to apple seeds in their appearance.11 Often times, there is a distinctive, characteristic ‘sweet’ odor associated with them.
How Long They Live
While they may be difficult to detect early in the course of infestation, a bed bug population can exponentially increase within a month. A bed bug’s typical lifespan averages from 6 to 24 months, and an adult female could lay 200-500 eggs during this time.15 If a host is available they will feed every 3 to 7 days.15 However, if no host is available, bed bugs can survive 12 months without feeding.11
What Attracts Them and How They Feed
Bed bugs feed on blood and are attracted to carbon dioxide and heat that the body gives off. Hosts are typically bitten at night on exposed skin and an insect will feed for 10 to 20 minutes until completely engorged.15 The bed bug has an elongated feeding organ, which is composed of two tubes. The first tube secretes several substances, including an anesthetizing compound (producing a painless bite that may be undetectable for hours), proteolytic enzymes and anticoagulants (to keep the blood from thickening). These substances are responsible for the subsequent skin reactions.11 The second tube simultaneously extracts the blood meal.
Bed bugs do not stay on the body of the host after feeding. Unable to fly or jump, they have six legs with which they are able to swiftly slip into crevices and evade detection.17 While they are most active in temperate environments, bed bugs exhibit incredible tolerance for temperature extremes and have been demonstrated to require 1 hour of exposure to temperatures lower than 3°F or greater than 118°F in order to be killed.18,19
How to Identify A Bed Bug Bite
The bites of bed bugs can closely resemble those of other insects; however, they tend to be clustered on skin that is freely exposed when sleeping, such as the face and hands and feet. Bites typically follow a linear path, or characteristically, appear in a group of three to five (commonly known as ‘breakfast, lunch, and supper’).22,23
In non-sensitized individuals, itchy, red spots on the skin may be the only evidence of bed bug bites.24 Bite sites typically appear as small itchy bumps, which form in response to components of the saliva injected by the bed bug. The bitemarks often have a spot of dried blood in the center.
Exaggerated skin reactions, such as large swollen welts, may occur in people whom have previously been bitten or are sensitive to other insects.25-27 Although rare, cases of asthma exacerbations, type I hypersensitivity allergic skin reactions, and severe anemia, secondary to bed bug bites have been reported.25,30
Insect bite reactions are often non-specific and, as such, are susceptible to misdiagnosis. Especially, if there is no visible evidence of a bedbug infestation. Bites from bed bugs have been incorrectly diagnosed and documented as:4
- Mosquito bites
- Spider bites
- Scabies
- Drug eruption
- Food allergy
- Staphylococcus infection
- Chicken Pox
Unfortunately, misdiagnosis can result in inappropriate or unnecessary treatment.
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Treatment and Management of Bites
OTC and At-Home Treatments
Most bed bug bites usually heal on their own within 1-2 weeks without any complications. For some, symptoms such as itching and swelling can feel intense, and may last several days. Luckily there are a variety of over the counter products that can offer relief.
To relieve itching and discomfort you can use topical anti-itch medications, such as Calamine lotion. Over the counter topical steroid creams including 0.5% and 1% Hydrocortisone are helpful, as well as topical anesthetics containing Pramoxine. Naproxen or Ibuprofen can be used to help with discomfort and pain.
Over-the-counter antihistamines such as diphenhydramine (Benadryl) are effective at reducing the symptoms of swelling. Antihistamines work by blocking the action of histamine on your cells. Your body produces histamines when it is exposed to allergens contained in the saliva of bed bugs. Histamines attach to cells in your body causing those cells to swell and leak fluid, and this is what leads to the symptoms of itching and swelling.
Other at-home-remedies include applying a warm washcloth directly to the skin. This may offer some relief to the skin, and reduce the desire to scratch. Applying witch hazel, St. John’s Wort and lemon juice to the bite may also help with itching.
The gel from the Aloe Vera plant is also helpful for treating bites. In addition to soothing the skin, aloe contains antifungal and antibiotic properties.
Medical Treatment
In rare cases, bed bug bites may cause secondary bacterial infections or systemic allergic reactions that require medical treatment.
Scratching excessively at a bite can break the skin, in some cases resulting in a bacterial infection. A doctor can administer a topical or oral antibiotic to help fight the infection.16
In some people, bed bug bites may cause a severe allergic reaction known as anaphylaxis. A doctor may administer an injection of intramuscular epinephrine or oral corticosteroids to reduce the symptoms. 16
A doctor may also administer prescription strength topical corticosteroid creams containing hydrocortisone to help relieve symptoms. For some people, using prescription topicals combined with the use of menthol and camphor can be soothing.
In addition to controlling the symptoms, eliminating the infestation must be aggressively pursued to prevent further bites. Goddard et al. (2009) have outlined several steps that are useful in successful eradication of bed bugs:16
- Proper identification of the bed bug in your home
- Notifying fellow building occupants, and landlord of the problem
- Thorough inspection of both infested and other nearby areas by a exterminator or pest removal specialist
- Implementation of pesticide and non-chemical control measures
- Follow-up to ensure control of the infestation
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Disease Transmission
In addition to skin and possible allergic reactions to bed bugs, the risk of disease transmission via bites has also been raised as a concern.33 There is both historical and experimental laboratory data supporting the Hepatitis B virus as a candidate for bed bug transmission.34 Further, a recent case report details the isolation of both vancomycin-resistant Enterococcus faecium (VRE) and Staphylococcus aureus (MRSA) bacterial colonies from bedbugs.35
How They Travel and Spread
Bed bugs can be introduced to an environment from either local or distant sites. Local transmission occurs by “active dispersal” as the insects walk short distances to find a source for feeding. This is the primary means of infestation in multi-unit dwellings, such as apartment buildings, as the bed bugs travel through ductwork, crevices in drywall, or electrical outlets. Infestation from distant sites occurs via “passive dispersal” when bed bugs can hitch a ride on clothing, luggage, or shipped furniture.11 As such, poorly maintained living conditions, overcrowding and transient populations can cause an increased risk of bed bugs.12 Unfortunately, this problem is difficult to manage. Local public health departments often have limited resources to combat this problem, and municipal regulatory bodies struggle to assign responsibility of high eradication costs to landlords or passing tenant populations. 13
Psychological Impact of Bedbug Infestations
The social and psychological impact of bed bugs can be devastating for affected individuals. Infestation can be stigmatizing due to the misconception that bed bugs are related to messy homes or poor hygiene. In reality, bed bugs are attracted to carbon dioxide and body heat and they are nourished by blood, not excrement or waste.6
Minimizing clutter can thus reduce hiding places where insects may remain undetected, but affected individuals can be reassured that they are not to blame. In addition to the stresses of identifying and controlling bed bugs in the home or workplace, some people may suffer anxiety due to fears of reinfestation even after the insects have been eliminated.20Extreme cases can result in delusions of imaginary bites.21
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