L20 Insect bites, stings, pediculosis

Types of bug bites ^^

mosquito (welt, pruritis)

flea (reddened, pruritic area around puncture, grouped bites)

chigger

deer tick

bedbugs

spider

when to refer for bug bites ^^

history of hypersensitivity to insect bites

younger than 2 yrs

infected bite area

deer tick bite (lyme disease(

spider bite

goals of therapy for bites ^^

prevent bites, relieve symptoms, prevent secondary bacterial infections

nonpharm prevention of bites ^^

cover skin with clothing, avoid infested areas, remove standing water around home, limit time outside, window screens, avoid scents

nonpharm relief of bite symptoms

ice pack 10 mins on 10 mins off

avoid scratching

comfy clothing

nail polish over chigger location

tick removal

1. use clean tweezers, get as close to skin surface as possible

2. pull upward, don’t twist/jerk, can cause pieces to stay inside skin but just take that out

3. clean bite area and hands with rubbing alcohol, soap, water

4. never crush tick with fingers, dispose someway else safer

otc options for bug bites

prevention - insect repellents (pretreating clothes with permethrin, skin-safe repellents

treatment - external analgesics (local anesthetics, counterirritants), topical hydrocortisone, skin protectants

follow up recommendations for bites ^^

symptoms of infection develop around bite

symptoms not resolved after 7 days

lyme disease

deet (safe to use on, less safe to use on, pk, moa, dosing)

n,n-diethyl-m-toluamide, not nonrx

skin, fabrics (nylon, natural fibers)

rayon, spandex, polyester, paints, vinyl products

48% penetration within 6 hrs, peak 1 hr, excreted in urine

unknown

apply as needed, check label

deet efficacy and toxicity

30% deet has 90% repellency, lasts 6-8 hrs w 25% deet

very rare toxicity, local reactions around eyes and skin

deet cautions ^^

avoid if hx of sensitivity, direct eye, nose, hand application

stop if dermatitis occurs

use sparingly, safe in preg

children: minimal use

• 6 mon-2 yr - 1 application/day

• 2-12 yr - 3 app

• max or 10% or less

picardin (vectors, child, ft, efficacy, moa, toxicity)

biting flies, mosquitoes, ticks

can use on children older than 2 month

odorless, will not damage plastic or fabric, nongreasy/nonsticky, less irritation

up to 20% effective for 8-10 hrs

dunno but suspected vapor barrier to prevent from biting

no toxicity, safe in pregnant

permethrin (vectors, ft, pk, dosing, efficacy, cautions)

ticks, fleas, blackflies

remains on clothing after washing

<1% absorption

apply to cloth, not skin

compared to deet, more effective against ticks, less against mosquitos

avoid eye/nose contact, wash hands after use, combo w deet

local anesthetics for bites (form, apply, se)

creams, ointments, aerosols, lotions

apply 3-4x daily up to 7 days

se: allergic contact dermatitis, skin irritation, avoid phenol under compresses

hydrocortisone for bites (apply, se, avoid)

appt 3-4x day up to 7 days

se: skin thinning

avoid infected skin

skin protectants for bites (ex, apply, se)

zinc oxide, calamine, titanium dioxide

apply prn up to 4x day

no signficiant se

presenting symptoms of stings

not allergic — pain, itching, irritation, rare systemic, possible delayed local inflammation 1-2 weeks later

allergic — hives, swelling, burning, possible anaphylaxis

when to refer for stings

hives, excessive swelling, dizziness, weakness, n/v, (get er asap), previous sting, younger than 2, previous reaction

treatment for insect sting care

remove stinger

ice pack in 10 min intervals

pharmacologic

• topical (hydrocortisone, local anesthetic, skin protectant, antiseptic, counterirritant)

• systemic (oral diphenhydramine, not topical)

follow up for sting ^^

emergency care

symptoms worsen during treatment

symptoms not resolved after 7 days of self care

stinger/venom sac removal

1. remove as quickly as possible (2-3 mins needed for venom sac to empty)

   1. dont use tweezers, releases more venom,

   2. scrape w fingernail or credit card, no squeezing

2. clean site w hydrogen peroxide or alcohol

transmission and symptoms of head lice

direct head-to-head contact, sharing hats, infested combs, towels (uncommon bc can die in 2 days w/out blood source)

pruritis

head lice life cycle

eggs/nits - 6-8 days

nymphs - 9-12 days to maturity, must feed within 24 hrs or will die

adults - cause infestations, crawl, 24-48 hr survival without host blood, live 30 days if blood meals

female life - lay 7-10 eggs per day, cemented to hair base

when to refer for lice

< 2 yrs of age for pyrethrins

<2 months of age for permethrins

< 6 months for ivermectin

hypersensitivity

infestation

preg/lact

cdc head lice treatment

check family members of infested, only treat if infested, treat everyone at the same time

retreatment recommended

headwear, linen, avoid sharing objects w hair, hot water, drying cycle, clean

nonrx drugs for head lice

pyrethrum, permethrin, ivermectin, dimethicone

pyrethrum (moa, app, dose, retreatment, tox, age)

kills live lice, not eggs/nits (lice seizures)

apply to shampooed (no conditioner), towel-dried air, comb w lice comb after treatment

check hair 8-12 hrs later, refer if not all dead, comb every 2-3 day x 2-3 weeks

retreat day 7-10

avoid if allergic to chrysanthemum, have irritation, redness pruritis, swelling, avoid mucous membranes

use in children 2 yrs+

permethrin (moa, app, check, toxicity, age)

neurotoxic to lice but not nits

wash hair first, no cond, towel dry, cover hair w product for 10 mins

check comb and hair 8-12 hrs later, refer if no dead lice

retreat day 10

check comb 2-3 day x 2-3 weeks

itching burning stinging, scalp irritation, avoid contact with mucous membranes

use in child 2 months+

ivermectin (moa, apply, avoid, toxicity, age)

binds to chloride channels on louse nerve and muscle cells, increased louse death

apply to clean dry scalp and hair, cover hair, 10 min wait, comb

avoid shampooing 24x after application

single otc treatment, still present then refer

minimal toxicity, scalp and eye irritation

use child 6 months+

dimethicone (moa, apply, wash, remove, toxicities, age)

coats eggs and live, blocks oxygen intake, dehydrates eggs

apply to clean dry scalp and hair, cover, comb, protect eyes leave for 10 mins

wash hair w reg shampoo, towel-dry hair

remove in sections starting w top of hair, soak comb in hot water above 130°F for 10 mins, check in 7 days, repeat if lice still present

minimal toxicities, temporary skin irritation or itching

no limits on age

wet combing

wet hair, fine toothed comb for anyone

each session 15-30 mins (longer for longer hair)

comb until no live found in session, repeat every 2-3 days until 2 weeks after last adult louse found