How to diagnose infestations accurately and implement powerful decontamination strategies to combat the rising prevalence of scabies, bedbugs, and lice.
Review: Scabies, Bedbug, and Body Lice Infestations. Image Credit: Pavel Krasensky / Shutterstock
In a recent review published in JAMA, researchers described the prevalence, causes, and treatment of infestations from scabies, bedbugs, and body lice, which frequently lead to itching and rashes.
They concluded that accurate diagnosis requires considering social factors like housing status and that effective treatment involves both medication and decontamination measures.
Background
Ectoparasites are parasites that live on the body's surface or in the environment, and infestations with scabies, bedbugs, and body lice are common. In 2021, about 622 million cases of scabies were reported globally, especially in low- and middle-income tropical regions and among children.
Scabies outbreaks also occur in shelters, nursing homes, and other group settings in wealthier countries. Bedbug infestations have risen since the late 1990s due to urbanization, travel, and insecticide resistance. Body lice are common among homeless populations, with prevalence ranging from 4% to 35%.
About the study
Researchers summarized the causes, symptoms, diagnosis, treatment, and outcomes of scabies, bedbugs, and body lice infestations. They searched a well-known medical database for studies published between 2014 and 2024 to gather the most relevant information.
They focused on high-quality studies that would be most useful to general clinicians, such as systematic reviews, clinical trials, and guidelines. Out of 821 studies found, 88 were included in the review.
These studies included clinical trials, meta-analyses, reviews, and public health resources. The goal was to provide a comprehensive overview to help clinicians better understand and manage these infestations.
Untreated scabies infestations cause infections
Tiny mites that live in the skin cause scabies. These mites lay eggs, which hatch and develop into adults in about two weeks. It usually takes four to six weeks for people to show signs of infection after exposure, such as itching and skin rashes.
The infection spreads through close contact, such as skin-to-skin contact or living in crowded conditions, and is more common in places like shelters or care facilities. A tell-tale sign of scabies is burrows, small thread-like marks on the skin. These are most often found in areas like between the fingers, wrists, ankles, and buttocks.
In severe cases, like crusted scabies, there are many more mites, and the skin becomes thick and scaly. If left untreated, scabies can lead to bacterial infections, which may cause serious health problems.
Diagnosing scabies can be difficult, but it is usually done through physical examination and testing of skin samples. Treatment typically involves medicated creams or oral medications, and close contacts are often treated as well to prevent spread.
Preventing and addressing bedbug infestations
Bedbugs are small, flat insects that feed on human blood. They are commonly found in places like mattresses, furniture, and walls. They are most active at night and are attracted to body heat and carbon dioxide.
Two main types of bedbugs bite humans: the common bedbug and the tropical bedbug. Bedbug bites often cause itchy red bumps on the skin, typically in the neck, arms, and legs. These bites can sometimes appear in clusters or lines, often described as the "breakfast, lunch, and dinner" pattern.
People who stay in places with frequent guest turnover, like hotels or shelters, are at higher risk of encountering bedbugs. Bedbugs are not known to spread diseases, but their presence can cause stress, anxiety, and sleep disturbances.
Treatment for bites usually involves creams to reduce itching, but professional pest control is needed to fully get rid of the infestation. Methods like heat treatment, vacuuming, and insecticides are used, but bedbugs have developed resistance to some chemicals. Preventive measures include inspecting hotel rooms and secondhand furniture for signs of bedbugs.
Body lice linked to disease spread
Body lice are tiny insects that live in clothing and feed on human blood. They are common in people who cannot maintain good hygiene, such as those without access to regular washing, like homeless individuals or those in crowded conditions. Body lice live in the seams of clothing near the skin, feeding multiple times daily, but they do not burrow into the skin.
Signs of body lice include itchy red spots, particularly around the waist, legs, and upper back. These insects can cause more than just skin irritation. In some cases, they lead to bacterial infections or spread diseases like trench fever, relapsing fever, and epidemic typhus.
Treatment involves washing clothes and bedding in hot water or sealing them in a bag for two weeks if washing is not possible. Bathing regularly is key to preventing lice. In some cases, medications like ivermectin or permethrin can help, but they only offer short-term relief. Long-term solutions often require improved living conditions and access to hygiene.
Conclusions
In summary, accurate diagnosis and decontamination are vital to treating infestations and preventing infection and the spread of diseases.
Journal reference:
- Scabies, Bedbug, and Body Lice Infestations: A Review. Thomas, C., Valladares, H.C., Berger, T.G., Chang, A.Y. JAMA (2024). doi:10.1001/jama.2024.13896, https://jamanetwork.com/journals/jama/article-abstract/2823413