Clinical Pearls & Morning Reports
Published June 3, 2020
Bedbugs, including Cimex lectularius, the common bedbug, and C. hemipterus, the tropical bedbug, are flat, brown insects that bite humans to obtain a blood meal. A global resurgence of bedbugs has been observed in the past 30 years. Reasons behind the resurgence are multifactorial and include resistance to insecticide products currently in use. Read the NEJM Clinical Practice article here.
Q: Is it easy to identify bedbug infestations in the home?
A: Physicians are increasingly confronted with bedbug problems as patients present with cutaneous lesions that appear to be bites. However, for patients and doctors, associating these lesions with bedbug bites may be difficult, because many people do not know that their house is infested by bedbugs. The inspection of rest areas, such as beds, sofas, and their surroundings, must be conducted meticulously, which often requires an experienced professional. The presence of exoskeletons or bedbug dark fecal spots on the mattress and bedding is a clear sign of infestation.
Q: Are there psychological consequences of bedbug infestations?
A: The psychological consequences of bedbug infestations are often underestimated. Sleep deprivation, insomnia, or sleeplessness are commonly associated with infestation. Patients often are awakened by the itching due to bedbug bites. Bedbug infestations are also associated with psychological distress manifesting as nightmares, phobias, hypervigilance, insomnia, anxiety, avoidance behaviors, delusions of parasitosis, and personal dysfunction, with people worrying that they are being bitten at night. People living in an infested home may feel shame and social isolation.
A: Bedbug bites are painless and may occur on any exposed part of the body. However, bites and lesions commonly occur on exposed areas that are not covered by sheets and blankets, such as the arms, legs, feet, face, and neck. Skin lesions can be noticeable immediately after the person wakes up but sometimes develop over the following days. Pruritic, maculopapular, and erythematous lesions are the most common clinical presentation; the diameter is typically 2 to 5 mm but may be up to 2 cm. Other lesions include wheals, vesicles, and, less frequently, bullae and nodules. A central punctum at the bite site may be seen in some cases, but often this is not visible. It is difficult to clinically discriminate bedbug bites from other arthropod bites. Isolated case reports have described systemic reactions, such as diffuse urticaria, asthma, and anaphylaxis. Scratching of pruritic lesions may lead to secondary infections such as impetigo, ecthyma, folliculitis, cellulitis, or lymphangitis; their frequency is unclear.
A: Bedbugs have been shown to carry more than 45 infectious agents, and some experimental data have aroused concern that they might transmit disease. For example, laboratory experiments have shown the competence of C. lectularius as a vector of Trypanosoma cruzi, the agent of Chagas’ disease. Studies have shown that C. lectularius can acquire, maintain, and excrete viable Bartonella quintana, the agent of louse-borne trench fever, and Borrelia recurrentis, the agent of louse-borne recurrent fever, which might infect humans through skin lesions similar to the mechanism of the transmission by body lice. However, bedbugs normally do not defecate while or immediately after feeding. There are currently no known cases of transmission of any infectious agents by bedbugs to humans.