Scabies/Sarcoptes
Human-to-human spread. Clinical: intensely itchy papular rash (hands, wrists, elbows, webbing between fingers, penis, scrotum), or occasionally diffuse non-pruritic rash in immune suppressed patients (crusted scabies). Secondary bacterial infection is common.
- Dx: Skin scraping or adhesive tape (look for mites, eggs or feces).
- Rx: Lindane, etc.
Lice/Pediculosis
Three types:
-
- Head louse
- Body louse
- Pubic louse/“crab louse” (also found in eyebrows)
Frequent secondary infection.
- Dx: Find nits (eggs) firmly attached to hair.
- Rx: Topical agents and combing nits out.
Bed bugs/Culex
Itchy rash. No proven transmission of diseases (although some speculation). Bites may be grouped or in lines (breakfast, lunch and dinner).
Insect bites
Chiggers, biting midges (no-see-ums), flea bites: Often cause very itchy papular rashes or urticaria.
Myiasis
Invasive fly larva from eggs lain on clothing, etc. Lesions look like folliculitis or scattered small abscesses.