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Dermatology > ENVIRONMENTAL
Bedbug Bites
Article Last Updated: May 9, 2008
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Robert A Schwartz, MD, MPH, Professor and Head of Dermatology, Professor of Medicine, Professor of Pediatrics, Professor of Pathology, Professor of Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School
Robert A Schwartz is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Physicians, and Sigma Xi
Coauthor(s):
Anna Gorkiewicz-Petkow, MD, PhD, Associate Professor, Department of Dermatology, Medical University of Warsaw, Poland
Editors: Craig A Elmets, MD, Director of Dermatology, Departments of Dermatology, Pathology, and Environmental Health Sciences; Professor, The Kirklin Clinic, University of Alabama at Birmingham; Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University School of Medicine; Consulting Staff, Mountain View Dermatology, PA; Jeffrey J Miller, MD, Associate Professor, Department of Dermatology, Penn State University, Milton S Hershey Medical Center; Joel M Gelfand, MD, MSCE, Medical Director, Clinical Studies Unit, Assistant Professor, Department of Dermatology, Associate Scholar, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System
Author and Editor Disclosure
Synonyms and related keywords:
bed bugs, bedbugs, chinch bug, Cimicidae, Cimex lectularius, C lectularius, Cimex hemipterus, tropical bedbug, common bedbug, hepatitis B, hepatitis, American trypanosomiasis, Chagas disease, insect bite, Hemiptera
Background
Arthropod assaults on humans can have many manifestations clinically, histologically, and immunologically. Hemiptera is an order of insect species. This order of "true bugs" has piercing-sucking mouthparts and includes the family Cimicidae (bedbugs), which are blood-sucking ectoparasites of mammals or birds. All Cimex species organisms are reddish brown insects. Cimex lectularius are 5-7 mm in size. Females are slightly larger than males. Cimex hemipterus organisms are approximately 25% longer than C lectularius organisms. Females deposit fertilized eggs in cracks or crevices, with newborns emerging in 4-5 days.
Infestations of the bedbug seem to be increasing around the world at an alarming rate, possibly due to insecticide resistance.1 Resistance to pyrethroid insecticides is already widespread in the United States. New tactics may be needed for this escalating public health concern.
Pathophysiology
The mechanism of skin injury by arthropods depends on the structure of the mouthparts. These insects are categorized as vessel feeders if they insert the tip into a capillary or as pool feeders if they feed on the extravasated blood from damaged tissue. They often inject different pharmacologically active substances (eg, hyaluronidase, proteases, kinins), which may cause different skin reactions (eg, erythema, wheal, vesicle, hemorrhagic nodule). The type of reaction provoked depends on previous exposure; repeated bites may lead to an allergic reaction, which may lead to pronounced cutaneous manifestations. Some patients show a severe systemic hypersensitivity to arthropod allergens. The site of the bite can also become secondarily infected with bacteria infection and lead to ecthyma, cellulitis, and/or lymphangitis. Susceptibility to arthropod bites depends on many external factors (eg, occupation, conditions of employment, cohabitation with a variety of domestic animals, housing, climate, clothing). An arthropod is usually attracted to its host by body heat, carbon dioxide in exhaled air, vibration, human sweat, and/or odor. The Cimex (bedbug) genus attacks both mammals and birds. C hemipterus (the tropical bedbug) bites mostly humans and is found in warm climates, whereas C lectularius (the common bedbug) also attacks bats and domestic animals (eg, chickens). Bedbugs are 5-7 mm in length with reduced wings. The mouthparts are modified for piercing and sucking. They live between wooden floorboards, in furniture, in bed frames, in mattresses, or behind peeling paint. Bedbugs sneak out to grasp human skin with their forelegs, pierce the skin, and inject anticoagulant- and anesthetic-containing saliva. Bedbugs normally feed at night, usually approximately an hour before dawn. However, if the conditions are favorable, they also feed during the day. Feeding takes 3-12 minutes. In proper conditions, adult bedbugs can survive without a meal for a year or longer. Each female lays approximately 300 eggs in her lifetime. The eggs hatch in 10 days. The nymph stage lasts 6 weeks, undergoing 5 molts. Insect bites, including those from the bedbug, have been proposed as a factor contributing to the formation of a cutaneous reaction termed papular urticaria. Patients with papular urticaria have been shown to demonstrate immunoglobulin G antibodies to bedbug (C lectularius) antigens.2 Thus, immunoglobulin G against C lectularius, Cimex pipiens, and Pulex irritans in patients with papular urticaria may contribute the pathogenesis of this condition.
Frequency
United States
This infestation is relatively common.
International
This infestation is common and worldwide, a problem particularly in poor regions of the world. The rate of bedbugs (Cimex hemipterus) was 37.5% in children's beds from a rural region of The Gambia.
Mortality/Morbidity
Bedbug bites can create considerable anxiety and localized and occasionally systemic reactions. Sometimes, if the bite reactions are intensely pruritic, scratching with excoriations may be complicated by impetigo.
- Bedbugs may be a vector for hepatitis B3 and, in endemic areas, for American trypanosomiasis (Chagas disease). See Chagas Disease (American Trypanosomiasis) and Hepatitis B for more information on these diseases.
- Anaphylactoid reactions are well described. One case of an anaphylactoid reaction occurred in a 41-year-old businessman in a first-class urban hotel in America.
Race
All people are affected. No racial or ethnic predisposition is known.
Sex
No sexual preference is known in bedbug attacks.
Age
No age predisposition is known.
History
- The bites often occur at night because bedbugs are nocturnal, with peak activity just before dawn.
- Bedbugs are resourceful and opportunistic insects. In one well-documented daytime outbreak, its victims were all women who rode a particular English tram. Each woman had a peculiar band of erythema studded with bullae on the back of both calves.
- Visually searching beds for bedbugs may be useful. It may be more efficient to survey the corners of bed nets and mattresses.
- Bedbugs produce a peculiar pungent odor familiar to building inspectors and tenement dwellers.
- With a heavy infestation, specklike masses of dung may be evident behind wallpaper and at other sites. This dung contains blood elements.
- Confirming the diagnosis of a bedbug bite sometimes is difficult. Obtain a detailed history of the home environment, work conditions, and presence of domestic animals.
- As reported by Leibold et al4 in 2003, a disseminated bullous eruption with systemic reaction caused by C lectularius may occur, but is rare.
Physical
- Most commonly, exposed skin is affected.
- Bedbug bites are painless, but pruritus and purpuric macules may appear.
- Their distribution depends on the bite site (eg, face, neck, hands, arms, lower legs, generalized); however, they often are present on the face upon awakening in the morning.
- Papules, urticaria, or bullae may predominate together with signs of secondary infection. The bullae are only rarely severe.5
- A hemorrhagic puncta may be evident.
- If a person is not sensitized, no symptoms may be evident, only a purpuric macule at the bite site.
- Bites are often noted in linear groups of 3, sometimes called "breakfast, lunch, and dinner," evident as erythematous papules, sometimes with a prominent urticarial component in predisposed individuals.
Causes
Bedbugs can be seen anywhere, but they tend to occur in environments in disarray. Old furniture makes an excellent home for bedbugs. They also like to hide in the seams and folds of mattresses and in bed frames and springs.
Dermatitis Herpetiformis
Drug Eruptions
Ecthyma
Insect Bites
Pemphigus Herpetiformis
Scabies
Other Problems to be Considered
Papular urticaria6
Histologic Findings
Most reactions to bedbugs show a superficial and deep perivascular infiltrate containing mixed cells, with eosinophils being prominent rather than neutrophils. Eosinophils may be prominent among collagen bundles, or they may be absent.
Medical Care
Medical care depends on the clinical picture. Bedbug bites do not usually require any treatment. Apply local antiseptic lotion or antibiotic cream or ointment if secondary infection occurs. Creams with corticosteroids and oral antihistamines may be advised in the presence of allergic reaction.
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.
Drug Category: Corticosteroids
Have anti-inflammatory properties and cause profound and varied metabolic effects. Modify the body's immune response to diverse stimuli.
| Drug Name | Triamcinolone cream 0.1% |
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| Description | Anti-inflammatory for use with intense, localized allergic reactions. Treats inflammatory dermatosis that is responsive to steroids. Decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing capillary permeability. Use 0.1% cream. |
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| Adult Dose | Apply a thin film to affected areas bid |
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| Pediatric Dose | Apply a thin film to affected areas bid |
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| Contraindications | Documented hypersensitivity; fungal, viral, and bacterial skin infections |
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| Interactions | None reported |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Prolonged use, applications over large areas, and use of potent steroids and occlusive dressings may result in systemic absorption; systemic absorption may cause Cushing syndrome, reversible HPA axis suppression, hyperglycemia, and glycosuria.
Triamcinolone cream o.1% in intertriginous (skin fold) areas may result in striae. Consider a less potent steroid in those areas. |
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Drug Category: Antihistamines
Act by competitive inhibition of histamine at H1 receptor. Used to treat minor allergic reactions and anaphylaxis.
| Drug Name | Chlorpheniramine (Chlor-Trimeton, Telachlor, Aller-Chlor) |
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| Description | For use with intense, localized allergic reactions. Competes with histamine or H1-receptor sites on effector cells in blood vessels and respiratory tract. |
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| Adult Dose | 4 mg PO hs |
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| Pediatric Dose | 2 mg PO hs |
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| Contraindications | Documented hypersensitivity; asthma attacks, narrow-angle glaucoma, symptomatic prostate hypertrophy, bladder neck obstruction, and stenosing peptic ulcer |
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| Interactions | CNS toxicity increases with coadministration of other CNS depressants, TCAs, MAOIs, and phenothiazines |
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| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
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| Precautions | May cause significant confusional symptoms; do not administer to premature or full-term neonates |
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Deterrence/Prevention
- Using insecticides and eliminating bedbug hiding sites reduce bedbug infestations.
- A number of insecticides are effective, including permethrin. Diethyltoluamide is an excellent insect repellent.
- Permethrin spray can be applied to clothing.
- Combined use of permethrin-treated clothing and cutaneous diethyltoluamide may be considered. In an African survey of rural homes, bed nets impregnated with permethrin were responsible for the disappearance of bedbugs.7
- Encephalopathy may occur in children exposed to high concentrations of diethyltoluamide.
- Infant bedding can be treated separately with pyrethrums.
- To prevent bedbugs from gaining access to the bed, try inserting bedposts of bedbug-free beds into containers of paraffin oil. However, bedbugs can be resourceful; they have been known to climb walls and across ceilings to drop onto their victims during the night.
- Structural insect proofing can be performed to prevent the bugs from entering homes and beds, in addition to using control measures such as spraying infested buildings with insecticides (eg, malathion).
- Eradication of a bedbug infestation may require a professional exterminator.
- Because bites occur on exposed skin surfaces, advise affected individuals to wear nightclothes that cover as much skin as possible.
Complications
- Watch for and treat any secondary bacterial infection. Transmission of trypanosomiasis or hepatitis B is possible and might be considered in appropriate settings. The Medscape Hepatitis B Resource Center may be helpful.
Prognosis
- The prognosis for bedbug bites is excellent.
Patient Education
- Educate the patient and family about bedbugs and their habits.
- For excellent patient education resources, visit eMedicine's Bites and Stings Center. Also, see eMedicine's patient education article Insect Bites.
Medical/Legal Pitfalls
- Theoretically, failure to diagnose bedbug bites puts a patient at increased risk of hepatitis B or some other infection; because bedbugs may transmit disease, the physician may be at medicolegal risk if the patient develops any such infection.
Special Concerns
- Passenger ships provide conditions suitable for the survival and growth of many pest populations. Pest infestations were identified in 21 ferries, 18 with flies, 11 with cockroaches, and with 3 with bedbugs in a 2008 study.8
| Media file 1:
The bedbug, a flat, oval, reddish brown insect that turns violaceous after feeding. Courtesy of Colonel Dirk M. Elston, MD (from Elston, 2000). |
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Media type: Photo
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| Media file 2:
Bedbugs feeding on a human host. Courtesy of Colonel Dirk M. Elston, MD (from Elston, 2000). |
 | View Full Size Image | |
Media type: Photo
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- Romero A, Potter MF, Potter DA, Haynes KF. Insecticide resistance in the bed bug: a factor in the pest's sudden resurgence?. J Med Entomol. Mar 2007;44(2):175-8. [Medline].
- Abdel-Naser MB, Lotfy RA, Al-Sherbiny MM, Sayed Ali NM. Patients with papular urticaria have IgG antibodies to bedbug (Cimex lectularius) antigens. Parasitol Res. May 2006;98(6):550-6. [Medline].
- Ogston CW, Wittenstein FS, London WT, Millman I. Persistence of hepatitis B surface antigen in the bedbug Cimex hemipterus (Fabr.). J Infect Dis. Sep 1979;140(3):411-4. [Medline].
- Liebold K, Schliemann-Willers S, Wollina U. Disseminated bullous eruption with systemic reaction caused by Cimex lectularius. J Eur Acad Dermatol Venereol. Jul 2003;17(4):461-3. [Medline].
- Masetti M, Bruschi F. Bedbug infestations recorded in Central Italy. Parasitol Int. Mar 2007;56(1):81-3. [Medline].
- Scarupa MD, Economides A. Bedbug bites masquerading as urticaria. J Allergy Clin Immunol. Jun 2006;117(6):1508-9. [Medline].
- Lindsay SW, Snow RW, Armstrong JR, Greenwood BM. Permethrin-impregnated bednets reduce nuisance arthropods in Gambian houses. Med Vet Entomol. Oct 1989;3(4):377-83. [Medline].
- Mouchtouri VA, Anagnostopoulou R, Samanidou-Voyadjoglou A, Theodoridou K, Hatzoglou C, Kremastinou J, et al. Surveillance study of vector species on board passenger ships, risk factors related to infestations. BMC Public Health. Mar 27 2008;8:100. [Medline].
- Ackerman AB. Histologic Diagnosis of Inflammatory Skin Diseases. A Method by Pattern Diagnosis. Philadelphia, Pa: Lea & Febiger; 1978:294-302.
- Bartley JD, Harlan JH. Bedbug infestation: its control and management. Military Med. 1974;139:884-6.
- Burnett JW, Calton GJ, Morgan RJ. Bedbugs. Cutis. Jul 1986;38(1):20. [Medline].
- Burns DA. The investigation and management of arthropod bite reactions acquired in the home. Clin Exp Dermatol. Mar 1987;12(2):114-20. [Medline].
- Crissey JT. Bedbugs: An old problem with a new dimension. Int J Dermatol. Jul-Aug 1981;20(6):411-4. [Medline].
- Elston DM, Stockwell S. What's eating you? Bedbugs. Cutis. May 2000;65(5):262-4. [Medline].
- Fletcher MG, Axtell RC. Susceptibility of the bedbug, Cimex lectularius, to selected insecticides and various treated surfaces. Med Vet Entomol. Jan 1993;7(1):69-72. [Medline].
- Gbakima AA, Terry BC, Kanja F, Kortequee S, Dukuley I, Sahr F. High prevalence of bedbugs Cimex hemipterus and Cimex lectularis in camps for internally displaced persons in Freetown, Sierra Leone: a pilot humanitarian investigation. West Afr J Med. Oct-Dec 2002;21(4):268-71. [Medline].
- Harves AD, Millikan LE. Current concepts of therapy and pathophysiology in arthropod bites and stings. Part 2. Insects. Int J Dermatol. Nov 1975;14(9):621-34. [Medline].
- Honig PJ. Arthropod bites, stings, and infestations: their prevention and treatment. Pediatr Dermatol. Jun 1986;3(3):189-97. [Medline].
- Iqbal MM. Can we get AIDS from mosquito bites?. J La State Med Soc. Aug 1999;151(8):429-33. [Medline].
- Kinnear J. Epidemic of bullous erythema on legs due to bed-bugs. 2. 1948. 1948:55.
- Kumar S, Prakash S, Rao KM. Comparative activity of three repellents against bedbugs Cimex hemipterus (Fabr.). Indian J Med Res. Jul 1995;102:20-3. [Medline].
- Parsons DJ. Bedbug bite anaphylaxis misinterpreted as coronary occlusion. Ohio Med. Jul 1955;51(7):669. [Medline].
- Pipkin AC Sr. Transmission of Trypanosoma cruzi by arthropod vectors: anterior versus posterior route infection. Int Rev Trop Med. 1969;3:1-47. [Medline].
- Sansom JE, Reynolds NJ, Peachey RD. Delayed reaction to bed bug bites. Arch Dermatol. Feb 1992;128(2):272-3. [Medline].
- Stibich AS, Carbonaro PA, Schwartz RA. Insect bite reactions: an update. Dermatology. 2001;202(3):193-7. [Medline].
- Webb PA, Happ CM, Maupin GO, Johnson BJ, Ou CY, Monath TP. Potential for insect transmission of HIV: experimental exposure of Cimex hemipterus and Toxorhynchites amboinensis to human immunodeficiency virus. J Infect Dis. Dec 1989;160(6):970-7. [Medline].
Bedbug Bites excerpt Article Last Updated: May 9, 2008
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