A close examination of the patient’s scalp and hair was unhelpful, but a close look at the weave and seams of her dress revealed multiple nits and lice, consistent with a diagnosis of body lice.
Head lice and body lice are 2 different ecotypes of the species Pediculus humanus and occupy different environments on the body. They differ slightly in body shape caused by variable expression of the same genes.1 Body lice primarily live and lay eggs on clothing, especially along seams and within knit weaves. They travel to the skin to feed, causing significant itching in the host from the inflammatory and allergic effects of their saliva and feces. Additionally, body lice are vectors of several serious diseases including epidemic typhus (Rickettsia prowasekii), trench fever (Bartonella quintana), and relapsing fever (Borrelia recurrentis).1
A diagnosis of body lice is a sign of severe lack of access to basic human needs—uncrowded shelter, clean clothes, and clean water for bathing. A patient who has been given this diagnosis should be offered and receive a bath or shower with generous soap and warm water. Clothes should be cleaned with hot water (up to 149 °F) or discarded. Patients also may be treated once with topical permethrin 5% cream applied from the top of the neck to the toes in the event that mites survived bathing by attaching to body hairs. Any systemic illness or fever should be evaluated for the above epidemic pathogens. Patients should also be put in touch with social services and mental health services, as appropriate.
This patient received all of the above treatments and had already accessed social services. That said, she continued to struggle with housing instability.
Photos and text for Photo Rounds Friday courtesy of Jonathan Karnes, MD (copyright retained). Dr. Karnes is the medical director of MDFMR Dermatology Services, Augusta, ME.