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Bedbug Bites

Updated : January 9, 2023





Background

The class Cimicidae contains up to ninety species of “bugs,” albeit only a small percentage of them actually bite people (bed bugs are genuine bugs with specialized extended mouthparts). Cimex lectularius and also the tropical bed bug, Cimex hemipterus, are the two primary species that primarily bite people. Cimex lectularius is typically found in more temperate settings, while Cimex hemipterus is generally known in the extremes within 30 ° of the equator.

Several species have recently been observed to travel beyond their typical infection zones. The species more frequently connected to infestations in the US is Cimex lectularius. The primary host of nocturnal bloodsucking arthropod parasites known as bed bugs is the human being. Prior to the 1990s, when a resurgence caused by increasing foreign travel & insecticide-resistant strains started, bedbug infestation rates in the United States had been declining.

Professionals in Australian pest control noted a 4,500 percent increase in bed bug infections in 2006. All Fifty states in the USA have reported bed bug infections. According to statistics from 2012, “an estimated 1 in 5 Americans have either experienced a bed bug infection in their house or know someone who has.” Infestations are now found in workplaces, retail locations, healthcare services, & movie theatres, in addition to homes & hotels. Infestations of bed bugs can be found practically anywhere people sit or sleep.

Epidemiology

Most genders and all ages experience an equal prevalence of bed bugs. However, a higher prevalence has been observed among people who reside in regions with dense populations, such as residences, who move more frequently & stay at hotels, and who come from poorer socioeconomic backgrounds.

Unlike most other pest infestations, skin-to-skin and direct clothing-to-clothing transfer are uncommon with bedbugs since they are nocturnal and stay put on their hosts.

Anatomy

Pathophysiology

The majority of individuals who experience bedbug bite reactions do so as a result of an immune reaction to the proteins in the bedbug salivary. The many proteins found in bedbug salivary serve a variety of functions, such as preventing blood clots from forming in the host, preventing platelet aggregation, causing vasodilation, and possibly even acting as antimicrobials in some cases.

Bed bugs feed by injecting salivary through needle-like stylets that are placed into the dermis for feeding and removed afterward. Nitrophorin, a vasodilator, a factor X inhibitor, and apyrase are all administered intravenously by C. lectularius. IgG autoantibodies to C. lectularius antigens have been detected in patients who suffer from papular urticaria, & nitrophorin has been demonstrated to cause IgE autoantibodies that are specific to allergens.

Etiology

Carbon dioxide and the host’s body heat both attract bed bugs. Instead of flying and jumping, they approach the host by moving from the material’s cracks, where they hide when it’s not eating. Although humans are bed bugs’ preferred hosts, they will also feed on other warm-blooded creatures. C. lectularius can infest chicken buildings in the US and reduce egg output. Typically, bed bugs don’t live on people. If a host is sleeping, they only make contact with people once or twice a few days for blood feeding.

Blood feeding normally takes place between 1:00 & 5:00 AM while hosts are soundly asleep. Bedbugs emit aggregate pheromones, and when sleeping in materials & digesting their blood meal throughout the day, they maintain close proximity to one another. After finishing a blood meal, bed bugs use the group pheromones to move to a new location.

The length of the life cycle is variable and based on ambient conditions, and the female C. lectularius bed bug will deposit five to eight eggs per week for eighteen weeks at 23°C & 90 percent relative humidity if hosts are continuously accessible. The majority of human bites occur while victims are resting in contaminated beds. Bed bugs can live on other objects and items in the same space, and they can infest numerous places that people frequent.

Genetics

Prognostic Factors

The prognosis for bug bites is rather good overall. Bug bites have rarely been linked to anemia or serious adverse reactions, and there is little evidence to support the claims that C. lectularius and C. hemipterus are disease vectors.

The “itch-scratch cycle,” bacteremia infections from scratching, & insomnia brought on by stress from living in an infested home are the most frequent aftereffects of bug bites.

Clinical History

Clinical History

Because the insects are nocturnal and reach their peak activity shortly before dawn, bedbug bites frequently happen at night. The bedbug is tenacious and opportunistic. In a well-known daylight epidemic, the fatalities were all female passengers on a certain English tram. On the back of both calves of each woman was a strange ring of erythema studded with bullae. Skin reactions result from exposure to bedbug bites on a regular basis.

The time between the bite and the skin reaction got shorter with each exposure, going from a few seconds to roughly 10 days. Finding bedbugs visually may be possible. Examining the corners of bed nets and mattresses may be more effective. Additionally, these insects emit a strange, strong smell that tenement residents and construction inspectors are both familiar with.

Heavy infestations may leave speck-like mounds of excrement visible behind wallpaper and in other places. There are elements of blood in this excrement. They might adjust to working in a corporate office. It has been reported that bedbugs reside underneath an atypical human nail plate that is thickened by noticeable subungual hyperkeratosis, which is quite unusual since bedbugs typically do not survive on the host.

Physical Examination

Physical Examination

Most frequently, afflicted skin is exposed skin. Although there is no pain from bedbug bites, pruritus and purpuric macules could develop. Whether they appear on the neck, hands, lower legs, arms, or elsewhere depends on where they were bitten, although they are frequently visible on the face when you first wake up in the morning. Bullae, urticaria, or papules may predominate in addition to secondary infection symptoms. Rarely are the bullae severe.

There could be a hemorrhagic punctum seen. A purpuric macule at the bite site may be the only sign if a person is not sensitized, as opposed to any other symptoms. It may be necessary to distinguish between sweet syndrome and eczema multiforme since targetoid & edema plaques may be present. The bites, which appear as erythematous papules and are frequently observed in linear groups of three, are known as “breakfast, lunch, and dinner” in susceptible people.

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Differential Diagnoses

Ecthyma

Dermatitis Herpetiformis

Insect Bites

Scabies

Pemphigus Herpetiformis

Drug Eruptions

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Bedbug bite reactions are self-limited; the biting ends as soon as the patient is taken out of the afflicted area or as soon as the bedbug colony is eradicated. Treatment of symptoms is necessary when patients experience a severe pruritic response to the bites. Local antipruritic lotions and systemic antihistamines sold over the counter are frequently beneficial.

Creams containing moderate to mild corticosteroids may be needed if the eruptions are severe enough. To alleviate symptoms and lower the risk of microbial superinfection and cellulitis from repetitive scratching, antihistamines & topical treatment are utilized. As always, care should be taken when recommending steroid creams to individuals who have an infected or disturbed epidermis.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK538128/

Bedbug Bites

Updated : January 9, 2023




The class Cimicidae contains up to ninety species of “bugs,” albeit only a small percentage of them actually bite people (bed bugs are genuine bugs with specialized extended mouthparts). Cimex lectularius and also the tropical bed bug, Cimex hemipterus, are the two primary species that primarily bite people. Cimex lectularius is typically found in more temperate settings, while Cimex hemipterus is generally known in the extremes within 30 ° of the equator.

Several species have recently been observed to travel beyond their typical infection zones. The species more frequently connected to infestations in the US is Cimex lectularius. The primary host of nocturnal bloodsucking arthropod parasites known as bed bugs is the human being. Prior to the 1990s, when a resurgence caused by increasing foreign travel & insecticide-resistant strains started, bedbug infestation rates in the United States had been declining.

Professionals in Australian pest control noted a 4,500 percent increase in bed bug infections in 2006. All Fifty states in the USA have reported bed bug infections. According to statistics from 2012, “an estimated 1 in 5 Americans have either experienced a bed bug infection in their house or know someone who has.” Infestations are now found in workplaces, retail locations, healthcare services, & movie theatres, in addition to homes & hotels. Infestations of bed bugs can be found practically anywhere people sit or sleep.

Most genders and all ages experience an equal prevalence of bed bugs. However, a higher prevalence has been observed among people who reside in regions with dense populations, such as residences, who move more frequently & stay at hotels, and who come from poorer socioeconomic backgrounds.

Unlike most other pest infestations, skin-to-skin and direct clothing-to-clothing transfer are uncommon with bedbugs since they are nocturnal and stay put on their hosts.

The majority of individuals who experience bedbug bite reactions do so as a result of an immune reaction to the proteins in the bedbug salivary. The many proteins found in bedbug salivary serve a variety of functions, such as preventing blood clots from forming in the host, preventing platelet aggregation, causing vasodilation, and possibly even acting as antimicrobials in some cases.

Bed bugs feed by injecting salivary through needle-like stylets that are placed into the dermis for feeding and removed afterward. Nitrophorin, a vasodilator, a factor X inhibitor, and apyrase are all administered intravenously by C. lectularius. IgG autoantibodies to C. lectularius antigens have been detected in patients who suffer from papular urticaria, & nitrophorin has been demonstrated to cause IgE autoantibodies that are specific to allergens.

Carbon dioxide and the host’s body heat both attract bed bugs. Instead of flying and jumping, they approach the host by moving from the material’s cracks, where they hide when it’s not eating. Although humans are bed bugs’ preferred hosts, they will also feed on other warm-blooded creatures. C. lectularius can infest chicken buildings in the US and reduce egg output. Typically, bed bugs don’t live on people. If a host is sleeping, they only make contact with people once or twice a few days for blood feeding.

Blood feeding normally takes place between 1:00 & 5:00 AM while hosts are soundly asleep. Bedbugs emit aggregate pheromones, and when sleeping in materials & digesting their blood meal throughout the day, they maintain close proximity to one another. After finishing a blood meal, bed bugs use the group pheromones to move to a new location.

The length of the life cycle is variable and based on ambient conditions, and the female C. lectularius bed bug will deposit five to eight eggs per week for eighteen weeks at 23°C & 90 percent relative humidity if hosts are continuously accessible. The majority of human bites occur while victims are resting in contaminated beds. Bed bugs can live on other objects and items in the same space, and they can infest numerous places that people frequent.

The prognosis for bug bites is rather good overall. Bug bites have rarely been linked to anemia or serious adverse reactions, and there is little evidence to support the claims that C. lectularius and C. hemipterus are disease vectors.

The “itch-scratch cycle,” bacteremia infections from scratching, & insomnia brought on by stress from living in an infested home are the most frequent aftereffects of bug bites.

Clinical History

Because the insects are nocturnal and reach their peak activity shortly before dawn, bedbug bites frequently happen at night. The bedbug is tenacious and opportunistic. In a well-known daylight epidemic, the fatalities were all female passengers on a certain English tram. On the back of both calves of each woman was a strange ring of erythema studded with bullae. Skin reactions result from exposure to bedbug bites on a regular basis.

The time between the bite and the skin reaction got shorter with each exposure, going from a few seconds to roughly 10 days. Finding bedbugs visually may be possible. Examining the corners of bed nets and mattresses may be more effective. Additionally, these insects emit a strange, strong smell that tenement residents and construction inspectors are both familiar with.

Heavy infestations may leave speck-like mounds of excrement visible behind wallpaper and in other places. There are elements of blood in this excrement. They might adjust to working in a corporate office. It has been reported that bedbugs reside underneath an atypical human nail plate that is thickened by noticeable subungual hyperkeratosis, which is quite unusual since bedbugs typically do not survive on the host.

Physical Examination

Most frequently, afflicted skin is exposed skin. Although there is no pain from bedbug bites, pruritus and purpuric macules could develop. Whether they appear on the neck, hands, lower legs, arms, or elsewhere depends on where they were bitten, although they are frequently visible on the face when you first wake up in the morning. Bullae, urticaria, or papules may predominate in addition to secondary infection symptoms. Rarely are the bullae severe.

There could be a hemorrhagic punctum seen. A purpuric macule at the bite site may be the only sign if a person is not sensitized, as opposed to any other symptoms. It may be necessary to distinguish between sweet syndrome and eczema multiforme since targetoid & edema plaques may be present. The bites, which appear as erythematous papules and are frequently observed in linear groups of three, are known as “breakfast, lunch, and dinner” in susceptible people.

Differential Diagnoses

Ecthyma

Dermatitis Herpetiformis

Insect Bites

Scabies

Pemphigus Herpetiformis

Drug Eruptions

Bedbug bite reactions are self-limited; the biting ends as soon as the patient is taken out of the afflicted area or as soon as the bedbug colony is eradicated. Treatment of symptoms is necessary when patients experience a severe pruritic response to the bites. Local antipruritic lotions and systemic antihistamines sold over the counter are frequently beneficial.

Creams containing moderate to mild corticosteroids may be needed if the eruptions are severe enough. To alleviate symptoms and lower the risk of microbial superinfection and cellulitis from repetitive scratching, antihistamines & topical treatment are utilized. As always, care should be taken when recommending steroid creams to individuals who have an infected or disturbed epidermis.

https://www.ncbi.nlm.nih.gov/books/NBK538128/