Insect Bites/Parasites

Question 1

most easily seen nape of neck and above the ear - nits (eggs) can be found attached to hair shaft

Answer 1

pediculosis

Question 2

lice tx?

Answer 2

permethrin 1% cream

for resistant bugs use malathion or oral ivermectin in immunocompromised

Question 3

presents as severe pruritus 4-6 weeks after initial infestation

• excoriations of the web spaces, heel of the palm, wrist, elbows, axillae, genitalia and breasts
• head and neck infection in infants, elderly and immunocompromised
• burrows can be found with associated small vesicles and pustules

Answer 3

scabies

Question 4

who to treat when scabies are present?

Answer 4

entire household

Question 5

scabies tx?

Answer 5

permethrin 5% cream to entire body for 8-12 hours, repeat 1 week later

Question 6

immunocompromised tx of scabies

Answer 6

oral ivermectin, 1 dose

Question 7

crusted scabies tx?

Answer 7

ivermectin once a day on days 1, 2, 8, 9, 15 plus permetrhin daily for 7 days, then 2x a week till cured

Question 8

how to tx a scabies pt that has intense itching?

Answer 8

topical steroids or benadryl

Question 9

main tx for arthropod bites?

Answer 9

topical steroids

Question 10

breakfast, lunch, dinner bite

Answer 10

bed bugs

Question 11

how long must a tick be attached for risk of lymes disease?

Answer 11

must feed for at least 24 hrs to infect host, but 72hrs is more statistically significant

Question 12

stage 1 lymes

Answer 12

Classically an expanding bull’s eye erythematous lesion (erythema migrans)
Associated w/ flu symptoms w/ or w/o fever (HA, arthralgias, myalgias, fatigue)

Question 13

stage 2 lymes

Answer 13

can occur 1-4 weeks after EM
Neuro: Bell’s Palsy, “aseptic” meningitis (mild)
Cards: myopericarditis w/ atrial or ventricular arrhythmias or heart block

Question 14

stage 3 lymes

Answer 14

manifests primarily as musculoskeletal, neurologic and skin sx/symptoms
- classically presents as monoarticular or oligoarticular arthritis with the knee disproportionately swollen compared to pain

Question 15

Acrodermatits chronica atrophicans

Answer 15

blue/red discoloration -> atrophic and sclerotic

rare side effect that can occur up to 10 years later

Question 16

gold standard test for lymes

Answer 16

B. burgdorferi culture

Question 17

confirmatory test for lymes

Answer 17

western blot

Question 18

most accessible test for lymes

Answer 18

Indirect Immunofluorescence Assay (IFA)

Question 19

IgM and IgG results from lyme

Answer 19

IgM-first appears 2-4 weeks post-exposure
- peaks at 3-6 weeks
IgG-first appears 4-6 weeks post-exposure
- peaks 4-6 months

Question 20

how is early lymes actually diagnosed?

Answer 20

cliniwhecal symptoms

Question 21

how is late lymes dx?

Answer 21

clinical symptoms and lab testing

Question 22

what if the pt has non-specific symptoms?

Answer 22

no lab testing required

Question 23

under what cirucumstances would you begin lymes prophylaxis?

Answer 23

1. adult or nymph I. scapularis identified and known to be attached for 36hrs
2. prophylaxis is started within 72hrs of tick removal
3. more than 20% of ticks in area known to be infected w/ B. burgdorferi
4. no contraindication for doxycycline (pregnant, allergic, 8 or younger)

Question 24

stage 1 tx?

Answer 24

Doxycycline 100mg BID x2-3 weeks

Question 25

stage 2 tx?

Answer 25

ceftriaxone, cefotaximine or PCN G plus doxy