Treating symptoms and cause
Management of bed bugs consists of symptomatic treatment of the bites and elimination of the infestation—treating both patients and their environments.15
Treating patients
Treating bed bug bites mainly involves providing symptomatic relief with antipruritic agents (antihistamines, topical or oral corticosteroids, over-the-counter topical anesthetics).16 When, rarely, a bite becomes infected, antibiotics may be indicated. Address psychological distress associated with an infestation. Counseling with cognitive behavioral therapy is effective most of the time, although some cases may warrant short-term psychopharmacotherapy.
Symptomatic relief will be short-lived, however, without remediation of the underlying infestation. If the bugs remain, the biting will continue.
Treating the environment
Every object and location in which bed bugs may have taken refuge must be treated. The first step in eradicating an infestation is to find it. In light infestations, evidence may be limited. However, they are dirty bugs. Significant amounts of litter, including molted exoskeletons, dark feces, and eggs, are found wherever there is an infestation. These signs of infestation may be found on mattresses or box springs, or in the bottom of bureau drawers and the corners of rooms. Anywhere just out of reach of the vacuum cleaner can harbor their detritus. Some success has been reported using bed bug detectors/monitors.17 Bed bug-sniffing dogs have been trained and employed in both identifying infestations and monitoring the efficacy of eradication interventions.
A number of extermination methods have been used. The most commonly used chemicals are permethrins, the same agents that have proven effective in antimalarial bed net programs. This agent is applied to the environment, not to the patient. Generally, at least 2 applications are required. Although as recently as 1990 no bed bug resistance to permethrin had been reported,18 there is now widespread resistance.19 Efforts at developing new agents are progressing.
Besides resistance, toxicity to humans is a concern. The Centers for Disease Control and Prevention (CDC) has reported both morbidity and mortality from chemical pesticides used in bed bug extermination efforts.20,21
Physical methods have also been applied.
Thermal treatment (heating or steaming to >48°C [120°F] for one hour or freezing to -20°C [-4°F] for one hour) has proven effective.22 Books, clothing, and other small items may be placed in an oven or freezer (as long as specified temperatures are met); steamers are useful for treating furniture and baseboards. If an oven is used, diligent attention must be paid to avoid too high a temperature, which could create a fire hazard. Let patients know that, even at 120°F, some book bindings and slipcovers could be damaged.
Desiccant dusts such as silica gel and diatomaceous earth, applied along the baseboards and the back of bookshelves, have also demonstrated efficacy.23 As with chemical pesticides, it is important to follow directions when using desiccant dusts to minimize potential health hazards.
The CDC recommends a comprehensive, integrated pest management program to control bed bugs. This program includes a number of methods, such as removing clutter and sealing cracks and crevices where bed bugs take refuge, applying heat treatment, vacuuming, using nonchemical pesticides, and cautiously applying effective chemical pesticides.17 An approach such as this is labor- and time-intensive, and can be costly.
Given the inadequacies of current strategies in controlling infestations, new approaches are needed. One such approach may be xenointoxication, in which patients take an oral arthropodicidal agent, making the blood meal toxic to the parasite and decimating the population. Although there are no literature reports of its application to bed bugs, the technique, using ivermectin, has been successfully applied to other ectoparasites, including scabies,24,25 lice,25,26 and the medically important arthropod vectors Triatoma27 and Anopheles.28 The TABLE shows dosing recommendations for 3 of these indications.
In vitro studies demonstrate that Cimex is susceptible to this same class of agents,29 so there is reason for optimism. Future studies will reveal the viability of this approach. Another potential approach to bed bug control is targeting the Wolbachia endosymbionts. Elimination of these bacteria has been associated with a significant decrease in parasite reproduction9; this strategy has also been efficacious in treating human filarial infections.30
TABLE
Xenointoxication with ivermectin has proven effective against several ectoparasite infestations24-28
| Ectoparasite | Condition | Ivermectin dosing |
|---|---|---|
| Sarcoptes scabiei | Scabies | 0.2 mg/kg, single dose |
| Pediculus capitis | Head lice | 0.2 mg/kg every 10 days x 2 doses |
| Pediculus corpora | Body lice | 0.2 mg/kg every 7 days x 3 doses |
In vitro research has shown that bed bugs are also susceptible to this class of antiparasitic drugs.
Preventing infestation