Bedbugs

Bedbug infestations occur throughout the world. The most common bedbugs affecting humans are Cimex lectularius (in temperate climates) and C. hemipterus (mainly in tropical climates); however, due to the rise of international travel and immigration, infestations have been reported outside their usual geographic distribution (1). Bedbugs undergo 5 nymphal stages of development; a blood meal is necessary for each nymph to advance to the next stage and mature into an adult form (2).

Bedbugs hide in cracks and crevices of mattresses and other structures (eg, bed frames, cushions, and walls in areas with less than optimal living conditions) (3). They multiply exponentially; a few bedbugs can multiply to thousands within 2 to 3 months. They move slowly and are attracted to people by warmth and carbon dioxide.

Bedbugs bite exposed skin, usually at night. A feeding is completed in 5 to 10 minutes. Although bedbugs can harbor > 40 types of infectious organisms (eg, Borrelia, Rickettsia, Trypanosoma species), they are not known to transmit these infections to humans (4).

Lesions are generally found on exposed skin and develop some time between the morning after and 10 days after being bitten. Lesions can present as any of the following:

• Puncta only

• Purpuric macules

• Erythematous macules, papules, or wheals, often pruritic and each with a central hemorrhagic punctum

• Bullae

Lesions may form linear patterns or may be seen in groups, arranged in the characteristic "breakfast, lunch and dinner" sign (1). Localized papular urticaria may develop after bedbug bites, which is thought to reflect host immune responses to the salivary protein of the bedbug. Older adults develop symptoms less often than do younger people. Lesions resolve after approximately 1 week. Secondary infection can develop.

Bedbug Bites

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© Springer Science+Business Media

Bedbugs have been associated with several mental health effects such as sleep disturbances and anxiety (2). Patients may be anxious about the difficulty and expense of eradicating a bedbug infestation and about the social stigma that can result from infestation. They may isolate themselves to avoid spreading infestation.

• History and physical examination alone

Diagnosis based on lesion appearance may be difficult because the appearance of bedbug bites is usually nonspecific. However, most bedbug bites are larger and more edematous than other bites (eg, flea bites).

Bedbug

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Image courtesy of CDC/DPDx.

Bedbug (Frontal View)

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Image courtesy of CDC/Harvard University, Dr. Gary Alpert, Urban Pests–Integrated Pest Management (IPM); Dr. Harold Harlan; and Richard Pollack via the Public Health Image Library of the Centers for Disease Control and Prevention.

Identification of bedbugs can help confirm the diagnosis. Bedbugs emit a characteristic musty, sweet odor from specialized glands (sometimes described as berry-like), which can be detected by trained sniffer dogs (1). On inspection, bedbugs have flat, oval, reddish brown bodies. After a blood meal, the body is less flat and more reddish. Adult Cimex lectularis are approximately 5 to 7 mm in length, and C. hemipterus are slightly longer. Bedbug feces or blood may be evident on bed linens or behind wallpaper.

• Symptomatic treatment

• Eradication and prevention of infestations

Bedbug bites are treated symptomatically (eg, with topical glucocorticoids and/or systemic antihistamines) as needed.

Eradicating bedbugs is difficult and is closely linked to detection. Eradication typically requires a multipronged approach and includes accurate detection and monitoring techniques, nonchemical modalities, and chemical agents. Nonchemical control options include exposure to extreme temperatures, exclusion, and physical removal (1).

Physical removal includes vacuuming affected areas and laundering suspect articles, then drying them on the dryer's hottest setting. In addition, environmental inspection by a professional pest management service may be needed. If a bedbug infestation is confirmed, entire rooms should be treated professionally, when possible, by heating to temperatures ≥ 50° C (122° F) or with multiple insecticides. The use of insecticides is limited largely because of growing resistance. Bedbugs and eggs on infested items are killed when frozen at -20° C (-4° F) for at least 2 hours; however, placement in most home kitchen freezers is typically insufficient (2).

Prevention methods include the use of simplified furniture (eg, metal beds). Harborage of bedbugs can be reduced by sealing cracks and crevices. New sleeping areas (eg, hotel rooms) should be inspected prior to use, with particular attention to the mattress and bedding (1).