Pediatric emergency medicine trisk 1809 1809

to examine their skin when possible. In contrast to adults, infants may develop
blisters and exhibit lesions on the head and face.
The diagnosis is made by scraping involved skin and looking for mites under
the 10× microscope objective ( Fig. 88.5 ). Once an infestation occurs, it usually
takes 1 month for sensitization and pruritus to develop.

FIGURE 88.5 Scabies mite.

Louse Infestation
Three forms of lice infest humans: (i) the head louse, (ii) the body louse, and (iii)
the pubic or crab louse ( Fig. 88.6 ). The major louse infestation in children
involves the scalp and causes pruritus. The female attaches her eggs to the hair
shaft. The egg then hatches, leaving behind numerous nits that resemble dandruff.
Secondary infection can occur from vigorous scratching. Body lice generally
reside in the seams of clothing and lay their eggs there. They go to the body to
feed, particularly the interscapular, shoulder, and waist areas. Red pruritic puncta
that become papular and wheal-like then occur. Pubic lice occur in the genital
area, lower abdomen, axillae, and eyelashes. Transmission is usually venereal.