Bites and Infestations

Question 1

main lice organisms (3)

Answer 1

pediculosis humanis var. captitis- head louse

body louse- corporis

pubic or crab louse- phthirus pubis

Question 2

pres of lice

Answer 2

scalp pruritis w/ or w/o posterior cervical lymphadenopathy

adult lice or nits can be found- most common on proximal hair shafts of occipital scalp- not movable along hair shafts

Question 3

timespan of lice

Answer 3

live 30 days on scalp, eggs ahtch in 8-12 days and viable for 10 days off scalp

Question 4

presence of ___ indicates active lice infection

Answer 4

live adults, immature nypmhs, or viable eggs

continued nit presence does not indicate active infection, w/o operculum cap they are not viable

Question 5

tx for pediculosis

Answer 5

physical removal

vacuum, wash linens, etc

OTC 1% permethrin lotion, but can cause resistance

topical ivermectin and malathion are available for resistant cases

Question 6

scabies mainly affects…

Answer 6

all ages and classes but more common in group settings, group homes, etc

more in infants and disables

Question 7

spread of scabies

Answer 7

direct contact, sometimes fomites

pres 3-4 weeks later

Question 8

pres of scabies

Answer 8

commonly erythematous papules at finger webs, waistline, umbilicus, breasts, scrotum

Question 9

skin finding of scabies

Answer 9

linear burrows in skin from mite movement, found easily in interdigital spaces, wrists, elbows

Question 10

describe crusted scabies

Answer 10

severe and contagious variant in disabled and immunocompromised pts

requires oral ivermectin

Question 11

most common bedbug

Answer 11

cimex lectularis

Question 12

“breakfast lunch and dinner” pattern of bites

Answer 12

from bedbugs, bites in a linear array

Question 13

timespan for bedbug life

Answer 13

can live 1 year w/o feeding

Question 14

contents of bedbug saliva

Answer 14

vasodilators, anti platelet agents, blockers of X to Xa

Question 15

bedbug tx

Answer 15

bites resolve

topical CS and/or abx

laundry and extermination

Question 16

red white and blue sign

Answer 16

zone of erythema around white central ischemia around blueish hemorrhagic bulla- from spider bite

Question 17

appearance of brown recluse

Answer 17

violin shaped brown marking

in midwest and southeas

Question 18

clin pres of brown recluse bite

Answer 18

can progress to necrosis and deep ulcer, need to rule out MRSA

Question 19

complicaitons/ tx of brown recluse bite

Answer 19

tissue necrosis from sphingomyelinase in venom

flu like sx, hemolysis, renal failure

supportive care and pain contrl tx

Question 20

scabies dx

Answer 20

mineral oil prep of skin scraping

Question 21

tx for scabies

Answer 21

topical 5% permethin cream

older than 2 mos and not pregnant