Field Guide to Venomous and Medically Important Invertebrates ...

Scabies mites produce two general types of lesions on the host including burrows and reddened
rash-like lesions. The burrows can be either intact or excoriated (open to the surface) and are
created by the female mite as she tunnels into human skin while laying eggs in the process. The
intact burrows appear as distinct raised, linear, and reddened marks, and those that are excoriated
can become secondarily infected resulting in the formation of pustules and encrustations.
Although infestations on a person may be widespread most are found on the extremities such as
hands, wrists, elbows, armpits, breasts, and genitalia. The reddened rash-like skin lesions are
most commonly found on the trunk while the burrows may be more generally distributed on the
patient. Secondary infections may result from scratching the bite site.
Figure 53. Rash in patient caused by bites from scabies mites. Photo: Seattle STD-HOV
Prevention Training Center, University of Washington.
Patients infested with scabies can be successfully treated with any of a variety of prescribed
topical chemical treatments that most commonly include permethrin as an active ingredient.
However, itching may still occur for several weeks following successful treatments which can be
minimized with use of topical corticosteroids and systemic antihistamines. Bed linens recently
used by scabies patients should be washed in hot water to reduce the chance of reinfestation.
Other medically important mites that bite people
Several other types of mites are occasionally known to attack humans, but such attacks are
relatively rare in comparison to chiggers and scabies mites. Unlike the chigger or scabies mites,
these mites feed on the host’s blood, and the initial bites are usually painful. They include the
chicken mite (Dermanyssus gallinae), spiny rat mite (Laelaps echidninus), house mouse mite