Slide 1. Sarcoptes scabiei
Under low-power magnification, the scabies mite is visible in this KOH preparation of skin scrapings from a burrow in a patient with scabies.

Slide 2. Demodex folliculorum (10x magnification)
This KOH preparation of follicle secretions shows the small worm-shaped mite, Demodex folliculorum, a normal inhabitant of human hair follicles. Ordinarily, the mites do not cause disease, but in large numbers they can produce papules, pustules, nodules, blepharitis, or follicular plugging with fine white scales, especially on the face.

Slide 3. Phthirus pubis (20x magnification)
The pubic, or crab, louse is about 1-mm long and has three pairs of legs with hook-like claws that enable it to grasp the body hairs on which it lives. Usually found in the pubic area, the lice also live on the abdomen, thighs, and axillae, or, uncommonly, on the scalp, face, eyelashes, and eyebrows.

Slide 4. Pediculus humanus corporis (20x magnification)
The body louse is about 3-mm long, lives and lays its eggs in the seams of clothing, and attaches to body hair when drawing a blood meal from its host. The louse in the photograph ate shortly before the slide was made. The head louse, Pediculus humanus capitis, looks similar, but lives in scalp hair, on which it lays its eggs (nits).