Insects, Bites, Stings and Parasitic infections

Scabies

- Parasitic infection caused by Sarcoptes Scarbei

- Female bites burrow in SC and deposit eggs into tunnels

Common sites of scabies

Between fingers, wrists, external genitals, buttocks. folds of skin

Inflammation and INTENSE itching, especially at night over trunk and limb areas

Characterization of scabies

Population and transmission of scabies

- Tends to affect clusters of people, esp those at institutions

- Transmission is thru physical contact; sometimes bleeding

- Incubation period is 3-4 weeks

Scabies: Rash

Small red papules and sometimes pustules; blisters and vesicles with skin excoriations and crusting

Scabies: Burrows

- Short elevated (red, brown, or gray)

- Straight or S-shaped lines found at wrist and between fingers. - Vary from 2-15mm long

Scabies types of lesion: Burrow

Linear tunnel in which mite lives

- other manifestations include papule, blisters, nodules and eczematous changes

Scabies site of involvement

Commonly involve web spaces, flex or surface of wrists, axillae, waist, feet, and ankles.

Sx of scabies

Itching, which is most severe at night

Scabies: First line Tx

Permethrin 5% cream 30g tube

Why is Permethrin 5% specifically the tx of choice and not the Permethrin 1%

Because the 1% is for head lice!! MAKE SURE TO KNOW THIS DIFFERENCE

How to apply Permethrin 5%

- From neck downwards on day 1 and once more after 1-2 weeks

How long should you leave Permethrin 5% on

Leave on overnight, and wash off after 8-14 hours

On children and infants, where else do you apply it?

Head and neck

Scabies: 2nd line Tx

Ivermectin 200 mcg/kg PO

Directions for Ivermectin 200 mcg/kg

Take by mouth on day one and once more after 1-2 weeks

When can ivermectin be first line

in large outbreaks or where topical treatment is impractical

Important considerations for scabies tx

Tx close contacts/family with unconfirmed infestation with permethrin 5% for one treatment

When can oral AHs be given for scabies

As adjunct for itching control during tx

What can improve the persistent itch and dermatitis after scabies eradication

Topical steroids

If scabies is suspected, what does the pharmacist need to do?

Refer patient to PCP for rx treatment

Hydrocortisone may be used in scabies when?

If we have a confirmed scabies diagnosis

Why can't hydrocortisone be used without a diagnosis

Because it may delay diagnosis and make burrows hard to see

Scabies: Eradication of mites

- Soak recently used bed sheets, pillowcases, and clothing in hot water and wash thoroughly

- Non washable items: seal in a plastic bag for 1 week

- Clean rooms thoroughly with normal household products

- Vacuum carpeted floors and upholstered furniture

- Treat close contacts to prevent reinfestation

Parasitic infections: Pinworm

- Most common worm infestation in the US

- Only helminthic infection with an approved OTC treatment

Pinworms are found with high prevalence in what settings?

Day care settings and urban areas

- Most common in pts 5-14 years old

T/F: Infection presents little risk to infected individual or public

True

Pinworm hosts

Only in humans

Most common route of transmission for pinworms

Direct anus-to-mouth transfer

- Eggs can also be transmitted from other surfaces to mouth

How long can eggs remain viable

20 days

Pt presentation of pinworms

- often asymptomatic

- perianal itching is most common sx, but happens at night

What are the symptoms of pinworms in a severe infestation (warranting referral)

- Vaginitis

- Vaginal bleeding

- PID

- Urethritis

- Dysuria

- UTI

- Hives

Identifications of pinworms

Adults are small, white and thread like with pin shaped pointed tail

What are some ways to inspect for pinworms

- Nighttime inspection using flashlight or tape sample

- Paddle test (best performed at night or early AM prior to bath)

Which inspection method is preferred

Paddle test

Tx goals for pinworm infections

- relieve symptoms

- eradicate pinworms to prevent reinfection

Tx approach for pinworms

Treat with pyrantel for patient and household members, in addition to strict hygiene

Pyrantel pamoate is available in what formulations

- liquid

- chewable tablet

- caplet

Pyrantel pamoate products

Pin-X, Pyrantel suspension, Reeses pinworm products

Exclusion criteria for pinworms

- Liver disease

- Pregnancy

- Breast-feeding

-

When should you follow up pinworm infections

2 weeks

Pyrantel MOA

paralyzes worms to allow expulsion by peristalsis

How is Pyrantel given and its dose

Single dose of 11mg/kg for adults/children >2 years

- Same dose used for children

Max dose of Pyrantel

1g

When can you repeat Pyrantel

repeat dose in 2 weeks

Counseling points for Pyrantel

Take any time of day without regard to meals and may be taken/mixed with milk or fruit juice

Pyrantel ADRs

GI side effects

Prescription options for pinworms

- Albendazole 400mg PO once on empty stomach; repeat in 2 wks

- Mebendazole 100mg orally once; repeat in 2 weeks

Which bites from insects are non-vemonous

Mosquitoes, fleas, bedbugs, ticks, chiggers

What are causes of reactions to insect bites

sensitivity to salivary secretions

Short term reaction to insect bites

irritation, discomfort, anaphylaxis

Long term reaction to insect bites

infection, disease

Mosquito borne illnesses

- West Nile

- Chikungunya

- Zika

- Malaria

What is important to consider with mosquito bites

Geographic exposure and recent travel history

Mosquito bites symptoms that require referral

- Fever

- Severe HA

- Myalgias

- Arthralgias

- Rash

- Systemic sx following exposure

Flea bites presentation

- Multiple and grouped, occurring primarily on legs and ankles

- Lesions characterized by erythematous region around puncture, and intense itching

Fleas carry what diseases

bubonic plague and endemic typhus

T/F: Fleas rarely, if ever, live on human hosts

True

What happens if a tick is left attached on an animal or human host

Tick becomes fully engorged with blood and stays attached for up to 10 days before falling off (longer attached, higher risk of Dz)

What is needed for tick bites

Prompt removal of the tick

Typical reaction to tick bites

itching papules that disappear within 1 week

Tick bite disease carrying capabilities

Rocky Mountain Spotted Fever and Lyme Disease; Alpha-gal

Tick removal

- Use tweezers to take tick off

- Pull upward using steady pressure. Do not twist, jerk or crush

- Clean skin and hands after removal

- Do it at the head and closest to the skin

- Pull slowly

If mouthparts of tick remain and cannot be easily removed, what should you do?

Leave it alone and allow the skin to heal. Body will push it out in time

What do you NOT apply to tick to make it detach

- Petrolatum jelly

- Nail polish

- Heat

- Other substances

If possible, do you keep the tick? Yes or no

Yes

Ticks: Rocky Mountain spotted fever transmission

Transmitted by wood ticks or dog ticks

Rocky Mountain spotted fever presentation

Fever, severe headache, myalgias, nausea, rash

Sx of Rocky Mountain spotted fever appear when?

3-12 days after tick bite

Tx of Rocky Mountain spotted fever

Doxycycline, Tetracycline

- Doxy is preferred for all patients and begin empirically if RMSF is suspected

Tick bites: Lyme disease

Inflammatory infection affecting joints, heart, and nervous system

Lyme disease is caused by what?

Deer ticks

If Lyme disease is left untreated, what can happen

neurologic, cardiac, and rheumatologic manifestations

Tx for Lyme disease

Patient may qualify for PEP with doxy for Lyme if they meet certain criteria

What criteria does a patient need to meet to get PEP with doxy for Lyme disease

- Tick identified as species capable of transmitting Lyme disease

- Exposure occurred in highly endemic area

- Estimated attachment duration of >36 hours

- Doxycycline can be started within 72 hours after tick removal

Acute stage of Lyme disease

- Flu like symptoms

- Rash at site, may enlarge to bulls eye

Later stage of lyme disease

Tender lesions/hives appear within 1 month; resolve in 3-4 weeks

long-term memory

Neurologic

Cardiac

Musculoskeletal

Alpha gal syndrome is caused by what?

Lone Star tick, most commonly in Southeast

What triggers the immune system to have an allergic reaction for alpha-gal syndrome

Bite transfers a sugar molecule called alpha-gal into the body and immune system to have mild to severe allergic reactions to red meat

Reactions for alpha-gal syndrome usually comes when?

2-6 hours after ingesting meat, and look similar to other food

allergies (hives, swelling, shortness of breath,)

T/F: Pts with alpha-gal syndrome may also cause reactions to other foods that come from mammals (dairy products, etc)

True

Tx options for alpha-gal syndrome

- Currently no treatment available

- Management includes avoidance of triggers, emergency preparedness with epinephrine, and allergy specialist evaluation

Chiggers live where?

shrubbery, trees, and grass

Chiggers are what

Larvae secrete digestive fluid that causes cellular disintegration of area, a red papule, and intense itching

Chiggers eruption usually starts when

Starts after the mites have already detached from the skin (6-12 hours after bite)

Most common location of chigger bites

- Lower legs (ankles, knees, calves)

- May see grouping along line of protected skin (ie along sock line, waistband line, etc)

Bed bugs do what?

Hide and deposit eggs in crevices of walls, floors, picture frames,

bedding, and furniture during the day; bite at night

Where are bed bugs most common

hotels and public areas

Bed bug bites apperance

Appear as a punctum , with or without a surrounding reaction

Bed bug bites usually resolve when?

Within a week without treatment

Preventing bed bugs

- Routine inspection of home

- When traveling: inspect room, pack clothing in storage bags, wash/dry clothing with high heat when returning; store suitcase in plastic bag for 2 weeks

- Preventative sprays

How to eradicate bed bugs

- Store sprays

- Pest control uses chemical insecticides to destroy bedbugs

- Vacuuming, heat treatment, laundering and freezing articles

- Washing/drying clothes and linens in dryer with hot settings

Repellants: DEET

Repellant for mosquitoes, ticks, and other labeled arthropods

Counseling points for DEET

Higher concentrations generally extend duration rather than improve protection

Repellants: Picaridin

EPA-registered alternative to DEET

Picaridin can be useful for patients when?

preferred by patients seeking a less greasy or low-odor formulation

Repellants: Oil of lemon/eucalyptus

Natural product option/alternative to DEET

Oil of lemon/eucalyptus cannot be used in what age groups

Not for use in children younger than 3 years old

Repellants: Permethrin 0.5%

Treatment of clothing, boots, and gear