Scabies, Bedbug, and Body Lice Infestations

Importance Scabies, bedbug, and body lice infestations are caused by organisms that live on or in the skin, on clothing, or in the environment and commonly cause pruritus and rash. In 2021, approximately 622 million incident cases of scabies occurred globally. Data on bedbug infestations are limited. Body lice prevalence ranges from 4.1% to 35% among persons experiencing homelessness worldwide. Observations Scabies is caused by mites ( Sarcoptes scabiei ) that burrow into the epidermis. Transmission primarily occurs from prolonged skin-to-skin contact with an individual who has an infestation. Common scabies is characterized by excoriated pruritic papules, plaques, and pathognomonic burrows on finger/toe web spaces, volar wrists, ankles, axillae, buttocks, male genitalia, and areolae. Permethrin cream and oral ivermectin are first-line treatments for adults, with similar clearance rates by week 2 (74% with permethrin vs 68% with ivermectin; relative risk, 0.91; 95% CI, 0.76-1.08). Treatment failure can occur with oral ivermectin (11.8%; 95% CI, 8.4%-15.4%) and topical permethrin (10.8%; 95% CI, 7.5%-14.5%). Bedbugs ( Cimex lectularius , Cimex hemipterus ) are insects that live on mattresses and furniture and feed on blood nocturnally, causing linear pruritic erythematous papules. New skin lesions on waking, cohabitants with similar symptoms, and recently residing in a high-occupancy setting should raise suspicion. Treatment requires eradication with pest management. Body lice ( Pediculus humanus humanus ) are insects found on clothing that travel to the skin for blood meals. Body lice bites cause pruritic excoriated macules/papules and hyperpigmentation in areas where clothing seams contact skin. Treatment and prevention require at least once-weekly bathing and laundering of clothing and bedding. Conclusions and Relevance Scabies, bedbug, and body lice infestations are common. Accurate diagnosis requires taking a history, including social drivers of health (eg, housing status, living environment), and physical examination. First-line treatments include scabicides for patients with common scabies and their close contacts. Scabies, bedbug, and body lice infestations should be treated with decontamination measures.