Skin nontumor
Infestations
Body & pubic louse
Last author update: 1 October 2016
Last staff update: 17 November 2020
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PubMed Search: (Body OR pubic) louse[TI]
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Differential diagnosisCite this page: Nagarajan P, Suo L. Body & pubic louse. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorbodylouse.html. Accessed June 4th, 2023.
Definition / general
- Defined as infestation caused by body louse (Pediculus humanus corporis)
- Skin lesions due to direct bite, hypersensitivity reaction and itching related excoriation
- Louse is also vector for other diseases such as epidemic typhus, trench fever and relapsing fever
- Pubic louse: often a sexually transmitted disease but can also be transmitted by sharing of towels or bedding (Wikipedia: Crab Louse [Accessed 28 August 2020])
Terminology
- Pediculosis, Pediculus humanus corporis
Epidemiology
- Found worldwide and affects people of all races and social classes (CDC)
- Highest in endemic areas, young, elderly, immunocompromised, nursing home residents and resource poor, overcrowded populations (Rev Chil Pediatr 2014;85:312)
Sites
- Lice live and lay eggs in clothing and bedding
- Usually do not live on human body, but are found only when they feed
Etiology
- Body lice prefer lower temperature and live and lay eggs in clothing and bedding
- Lice are bloodsucking insects, feeding ~ 5 times a day by biting host
- Small amount of louse saliva is injected into host during feeding, causing mild hypersensitivity reaction and associated pruritus
- Lice are vector for epidemic typhus (Rickettsia prowazeki), trench fever (Bartonella quintana) and relapsing fever (Borrelia recurrentis) (Clin Microbiol Infect 2012;18:332, Clin Lab Med 2015;35:847)
Clinical features
- Intense itching and irritation of the body
- Extensive excoriation, serous crusting and scaling on the body
- Identification: Body lice are about the size of sesame seeds and are found on clothing and bedding, while nits are found in seams of clothing or rarely attached to body hair
- Can be associated with secondary infections such as epidemic typhus, trench fever and relapsing fever (Infect Genet Evol 2014;23:209)
Diagnosis
- Thorough physical examination
- Dermatoscopy is a non invasive technique important for the diagnosis of skin infestation diseases (Clin Dermatol 2014;32:315)
- Histology examination is useful to find the diagnostic organism and to establish dermal hypersensitivity reactions associated with insect bites
Case reports
- Louse borne relapsing fever (Borrelia recurrentis) in asylum seekers from Eritrea, The Netherlands, July 2015 (Euro Surveill 2015:30;20)
- Dermoscopy applied to pediculosis corporis diagnosis (An Bras Dermatol 2014:89:513)
- An unusual autopsy case of lethal hypothermia exacerbated by body lice induced severe anemia (Int J Legal Med 2016:130;765)
Treatment
- Improving personal hygiene
- Systemic medication: oral ivermectin (Dermatol Online J 2016:16;22)
- Topical treatment: Lindane shampoo, benzyl alcohol 5% and permethrin
- Prevention: Improving personal hygiene, regular washing of clothes and avoiding direct physical contact with those who carry body lice
Clinical images
Images hosted on other servers:
Body louse
Scalp infection and scraping lesions
Pubic louse
Human infestations of pubic louse
Microscopic (histologic) description
- Skin lesion: perivascular lymphohistiocytic infiltrate mixed with variable numbers of eosinophils, arranged in a wedge shape that tapers towards deep dermis, rarely intradermal hemorrhage
- Body lice: 3 - 4 mm long, 3 pairs of legs, elongated body and thin head with narrow mouth parts
- Nits (eggs): small white structures, 1 mm long, teardrop shaped, translucent with apical operculum
Differential diagnosis
- Delusions of parasitosis: excoriations on histology, no bite pattern on histology
- Dermatophyte infection: PAS positive hyphae
- Non louse insect bites
- Scabies: similar bite pattern on histology; scabies or burrows may be seen in biopsies
