Bed bug

Bed bugs are a type of insect that feed on human blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects and allergic symptoms. Bed bug bites may lead to skin changes ranging from invisible, to small areas of redness, to prominent blisters. Symptoms may take between minutes to days to appear and itchiness is generally present. Some may feel tired or have a fever. Typically, uncovered areas of the body are affected and often three bites occur in a row. Bed bugs bites are not known to transmit any infectious disease. Complications may rarely include areas of dead skin or vasculitis. Bed bug bites are caused primarily by two species of the insect Cimex: Cimex lectularius (the common bed bug) and Cimex hemipterus. Their size ranges between 1 and 7 mm. They spread by crawling between nearby locations or by being carried within personal items. Infestation is rarely due to a lack of hygiene but is more common in high-density areas. Diagnosis involves both finding the bugs and the occurrence of compatible symptoms. Bed bugs spend much of their time in dark, hidden locations like mattress seams or cracks in the wall. Treatment is symptomatic. Eliminating bed bugs from the home is often difficult, partly because bed bugs can survive up to a year without feeding. Repeated treatments of a home may be required. These treatments may include heating the room to 50 °C (122 °F) for more than 90 minutes, frequent vacuuming, washing clothing at high temperatures, and the use of various pesticides. Bed bugs occur in all regions of the globe. Rates of infestations are relatively common, following an increase since the 1990s. The exact causes of this increase is unclear; with proposals including greater travel, more frequent exchange of second-hand furnishings, a greater focus on control of other pests, and increasing resistance to pesticides. Bed bugs have been known human parasites for thousands of years. Individual responses to bites vary, ranging from no visible effect (in about 20–70%), to small macular spots, to prominent wheals and bullae formations along with intense itching that may last several days. The bites often occur in a line. A central spot of bleeding may also occur due to the release of anticoagulants in the bug's saliva. Symptoms may not appear until some days after the bites have occurred. Reactions often become more brisk after multiple bites due to possible sensitization to the salivary proteins of the bed bug. The skin reaction usually occurs in the area of the bite which is most commonly the arms, shoulders and legs as they are more frequently exposed at night. Numerous bites may lead to an erythematous rash or urticaria. Serious infestations and chronic attacks can cause anxiety, stress, and insomnia. Development of refractory delusional parasitosis is possible, as a person develops an overwhelming obsession with bed bugs. A number of other symptoms may occur from either the bite of the bed bugs or from their exposure. Anaphylaxis from the injection of serum and other nonspecific proteins has been rarely documented. Due to each bite taking a tiny amount of blood, chronic or severe infestation may lead to anemia. Bacterial skin infection may occur due to skin break down from scratching.Systemic poisoning may occur if the bites are numerous. Exposure to bed bugs may trigger an asthma attack via the effects of airborne allergens although evidence of this association is limited. There is no evidence that bed bugs transmit infectious diseases even though they appear physically capable of carrying pathogens and this possibility has been investigated. The bite itself may be painful thus resulting in poor sleep and worse work performance.