Bed Bugs

Bedbugs (or bed bugs) are small, elusive, and parasitic insects of the family Cimicidae. They live strictly by feeding on the blood of humans and other warm-blooded animals. The name 'bed bug' is derived from the insect's preferred habitat infesting houses and especially beds or other common areas where people may sleep. Bedbugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on their hosts.

Largely eradicated as pests in the United States in the early 1940s, bedbugs have been resurgent in the past decade to near epidemic proportions.

Bites

Most observed bites consist of a raised red bump or flat welt, and are often accompanied by very intense itching. The red mark is the result of an allergic reaction to the anesthetic contained in the bedbug's saliva, which is inserted into the blood of its victim. Reactions to bedbug bites may appear indistinguishable from mosquito bites although they tend to last for longer periods. Bites may not become immediately visible and can take up to nine days to appear. Bedbug bites tend not to have a red dot in the center such as is characteristic of flea bites. A trait shared with flea bites is tendency towards the pattern of sequential bites often aligned in rows of three. This may be caused by the bedbug being disturbed while eating and relocating half an inch or so farther along the skin before resuming feeding. Alternatively, the arrangement of bites may be caused by the bedbug repeatedly searching for a blood vein.

People react differently to bedbugs, and individual responses vary with factors including skin type, environment, and the species of bug. This also means the presence of itchy welts cannot be used as the only indicator of a presence. It is possible for an initial infestation within a household to be asymptomatic and go undetected. In some rare cases, allergic reactions to the bites may cause nausea and illness. In a large number of cases, estimated to be fifty percent of all people, there is no visible sign of bites whatsoever, greatly increasing the difficulty of identifying and eradicating infestations. People commonly respond to bed bug infestations and their bites with anxiety, stress, and insomnia. Individuals may also develop skin infections and scars from scratching the bedbug bite locations.

Most patients who are placed on systemic corticosteroids to treat the itching and burning often associated with bedbug bites find that the lesions are poorly responsive to this method of treatment. Antihistamines have been found to reduce itching in some cases, but they do not affect the appearance and duration of the lesions. Topical corticosteroids, such as hydrocortisone, have been reported to resolve the lesions expediently and decrease the associated itching.

Victims may relieve itching and inflammation for several hours by using a blowdryer or hot washcloth to heat the area of the bite. Many patients experience temporary relief of itching and inflammation with the application of hot water. The water should be quite hot (about 50 °C / 120 °F), however, or this procedure may aggravate the symptoms. Thus, to avoid scalding the skin, this treatment should only be self-administered.

Disagreement exists as to why heat causes symptoms to abate. Varying hypotheses propose that heat overwhelms the nerve endings that signal itch, that heat neutralizes the chemical that causes the inflammation, or that heat triggers a large release of histamine, causing a temporary histamine deficit in the area. Another theory is that the heat denatures the proteins in the bedbug saliva, changing their composition enough so that they no longer trigger the body's defensive mechanisms.

Disease transmission

Bedbugs seem to possess all of the necessary prerequisites for being capable of passing diseases from one host to another, but there have been no known cases of bed bugs passing disease from host to host. There are at least twenty-seven known pathogens (some estimates are as high as forty-one) that are capable of living inside a bed bug or on its mouthparts. Extensive testing in laboratory settings concludes that bed bugs are unlikely to pass disease from one person to another. Therefore bedbugs are less dangerous than some more common insects such as the flea. However, transmission of Chagas disease or hepatitis B might be possible in appropriate settings.

Other effects on health

The salivary fluid injected by bed bugs typically causes the skin to become irritated and inflamed, although individuals can differ in their sensitivity. Anaphylactoid reactions produced by the injection of serum and other nonspecific proteins are observed and there is the possibility that the saliva of the bedbugs may cause anaphylactic shock in a small percentage of people. It is also possible that sustained feeding by bedbugs may lead to anemia. It is also important to watch for and treat any secondary bacterial infection. Systemic poisoning may occur if the bites are numerous.