Ch. 36 Insect Bites, Stings, and Pediculosis Flashcards
1
Q
Insect Bites, Stings, and Pediculosis
A
- 0.5% shown to have systemic reactions to insect stings
- 500+ stings can cause death from toxicity
- Pediculosis - lice infestation, effects 10-12 million per year, mostly kids from 3-12 y.o.
2
Q
Insect Bites
A
Nonvenomous, but have biting organs and saliva secretions that cause reactions
3
Q
Mosquitoes
A
- Found mainly in warm, humid climates
- Inject anticoagulant into victim causing the welt and itching
- Malaria and West Nile Virus are severe systemic infections transferred by mosquitoes
- 2012- 48 states reported W.N.V. - 20% of infected experienced fever and fatigue
- Can progress to muscle weakness, encephalitis, and meningitis
- Control mosquito population to prevent disease spread
4
Q
Fleas
A
- Tiny bloodsuckers found worldwide but breed best in humid climates
- Usually bitten by moving into a flea infested area or by having infested pets
- Usually multiple, grouped bites around legs/ankles
- Erythematous, itchy around puncture
- Can transmit bubonic plague and endemic typhus
5
Q
Sarcoptes Scabiei
A
- Scabies, “the itch,” contagious parasite infection caused by sarcoptes scabiei
- Very small, rarely seen arachnid mite
- Burrow up to 1 cm in skin, deposit eggs
- Common between fingers, on wrists, on butt, on penis, and in anterior armpit folds
- Inflammation and intense itching
- Transferred by contact and can only be treated by Rx
6
Q
Bedbugs
A
- hide and deposit eggs in walls, floors, picture frames, bedding, folds of linens, corners of suitcases, and furniture during day
- Bite their victims at night
- Increase mobility of people has increased the incidence of these infection
- Bites usually around head, neck, and usually cluster in 2-3 in a straight line
- Reaction can be anywhere from irritation to a small dermal hemorrhage
7
Q
Ticks
A
- Feed on human and animal blood
- Ticks mouthparts are introduced into skin making it hold tightly
- If mouthparts aren’t removed when the tick is, intense itching and nodules requiring surgery may develop
- If left attached, tick becomes engorged and remains for up to 10 days on the skin before falling off
- Remove intact tick within 36 hours of attachment
- Don’t use heat methods, nail polish, or petrolatum to remove tick since it can irritate it and increase its saliva secretions or cause it to regurgitate its contents
- Can cause itching papules for up to 1 week
- Some carry Rocky Mountain Spotted Fever and Lyme Disease
8
Q
Rocky Mountain Spotted Fever
A
- Severe headache, rash, fever, exhaustion
- Spread by dog or wood ticks
9
Q
Lyme Disease
A
- Cause by spirochete
- Spread by deer ticks
- Transmitted after being attach for 36 hours
- Common in NE/Midwest parts of U.S., reported in 46 states
- 1st: papule, then enlarged circle with a clear center called a “bulls-eye”
- Tender, urticarial lesion appears 3-32 days later and spontaneously disappears within 3-4 weeks
- If untreated, neurological symptoms, cardiac disturbances, and musculoskeletal symptoms and arthritis can occur
- Early diagnosis and health care treatment is needed to prevent these severe results
10
Q
Chiggers
A
- AKA red bugs, live in shrubs, trees, and grass
- Attach to skin and larvae secrete digestive fluid to cause cellular disintegration
- Creates red papule and intense itching
- Also causes skin hardening that forms a tube for a chigger to engorge until it drops off and becomes an adult
11
Q
Spiders
A
- All are poisonous but most can’t penetrate the skin due to short or fragile fangs
- Black widow, brown recluse, and hobo spiders are exceptions
- Death: rare, but symptoms are serious
- Black widow: delayed, intense pain, stiffness, joint pain, abdominal disturbances, fevers, chills, dyspnea
- Brown recluse: same symptoms but also a spreading, ulcerated wound at the bite site
- Hobo: moderate to severe, slow healing wound
- If spider bite is suspected but not confirmed, monitor wound area for symptoms
12
Q
Insect Bite Complications
A
- Secondary infections from itching
- Includes impetigo - yellow crusting, purulent discharge, significant redness and swelling
13
Q
Insect Bite Treatment
A
Non-Rx external analgesics for minor bug bites
14
Q
Insect Bite Treatment Goals
A
- Relieve symptoms
- Prevent secondary infections
15
Q
Insect Bites General Treatment
A
- Apply ice pack wrapped in a wash cloth to provide pain/irritation relief
- Apply for 10 minutes and space out at least 10 minutes between applications
- Use non-Rx topical analgesic if this doesn’t work
- Avoid scratching
- Okay to self treat if reaction ins confined to bite site and patient is > 2 y.o.
- Doctor referral: scabies, ticks, and spiders
16
Q
Insect Bite Nonpharmacologic
A
- Prevention
- Insect repellant
- Avoiding insects
17
Q
Insect Bite Avoidance
A
- Cover skin as much as possible
- Avoid swamps, dense woods, dense brush,
- Keep pets pest free
- Remove standing water from home
- Limit time outside at dusk and dawn
- Use window screens and netting
- Avoid infected individuals
- Apply insect repellant
18
Q
Insect Repellant
A
- Don’t repel stinging insects
- Choose based on ingredients, concentrations, and types/lengths of exposure
- DEET: 7-100%, may be combined with IR3535 or dimehthyl phthalate
19
Q
DEET
A
- Best all purpose repellant
- MOA: not fully understood, doesn’t kill insects
- Releases vapors that discourage insects
- Sprays, solution, wipes, creams, and other forms
- Frequency: q 4-8 h, on skin and cloths
- Use >30% for kids, non in less than 2 months
- 10-40% is adequate for adults in routine situations, 50-100% usually for adults in high, extended time exposure
- Higher concentrations have higher tendencies of skin reactions
- Heat and humidity can lower its efficacy
- Improper use/ingestion can lead to seizures, ataxia, hypotension, angioedema, encephalopathy
- Safe when properly used, even preggo/BF
20
Q
Other Repellants
A
- Citronella, lemon eucalyptus oil, soybean oil, cedar oil, lavender oil, tea tree oil, garlic, thiamin, and scented moisturizers in minieral oil
- Less effective than DEET, especially regarding length of action
- Picaridin, alternative to DEET, promoted as having less odor and irritation, 0.5%, only for clothes/camping equipment
21
Q
Insect Bites Pharmacologics
A
- Some local anesthetics, topical antihistamine, hydrocortisone, and counterirritants are approved for pain/itching
- Topical protectants can be used to reduce inflammation and increase healing
- Antiseptics and antibiotics can help prevent infection
- Systemic antihistamines often used for bite itching but not an indication
22
Q
Insect Bites - Local Anesthetics
A
- Benzocaine, pramaxine, benzyl alcohol, lidocaine, dibucaine, and phenol - approved for itching and irritation relief
- Cause reversible blockade on nerve impulse conduction and site
- Phenol depresses cutaneous sensory receptors
- Topical preparations are applied 3-4x per day for a max of 7 days
- Usually well tolerated with minimal systemic absorption other than allergic dermatitis
- Pramoxine and benzyl alcohol have less SE
- Dibucaine - common allergen that can cause systemic toxicity resulting in convulsions, myocardial depression, and death
- Phenol solutions >2% - irritating and can cause sloughing of skin and necrosis
- Don’t apply phenol to extensive areas of body of under compresses/bandages, don’t use in preggo or children
23
Q
Insect Bites - Topical Antihistamines
A
- Diphenhydramine - 0.5-2% most popular topical antihistamine agent
- Depresses cutaneous receptors and approved for temporary relief of pain/itching
- Many dosage forms, 3-4x per day with a max of 7 days
- Usually not absorbed enough to cause systemic SE
- Systemic absorption increases with extensivearea use and kids
- SE: photosensitivity, allergic reactions, continued use for 3-4 weeks can increase contact dermatitis risk
24
Q
Insect Bites - Counterirritants
A
- Low concentrations used in topical analgesics
- Generally appled 3-4x per day for up to 7 days
25
Insect Bites - Camphor
- 0.1-3%, depresses cutaneous receptors and relieves itching and irritation (anesthetic effect)
- VERY dangerous if ingested
- Keep out of kid's reach
26
Insect Bites - Menthol
- Concentrations <1% depresses cutaneous receptors and exert analgesic effect
- Considered safe and effective antipruritic when applied to effect area at 0.1-1%
27
Insect Bites - Hydrocortisone
- 1% indicated for temporary relief of minor bites
- Many dosage forms
- Apply to bite 3-4x day for a max of 7 days
28
Insect Bites - Skin Protectants
- Zinc oxide, calamine, and titanium dioxide are applied to bites as cream/lotion/ointment
- Act as protectants and decrease inflammation/irritation
- Zinc oxide: acts as mild astringent with weak antiseptic properties, absorbed fluids from weeping lesions
- Calamine - absorbed fluids from weeping lesions
- Calamine and zinc oxide are effective at 1.25%
- Titanium dioxide: similar MOA as zinc, biut its safety and efficacy aren't established
- Apply to AA prn, minimal adverse effects, and recommended for adults, kids, and infants
29
Insect Bites - Product Selection Guideline
- Sensitization can occur with local anesthetics
- If these are preferred, praoxime and benzyl alcohol have lowest incidence of ASE
- Phenol and dibucaine have the highest rate of ASE
- ASE and systemic absorption are not a concern with short-term use of topical antihistamines, prolonged use can cause photoallergic or allergic reactions
- Short-term hydrocortisone use is usually okay too
- Scabies, bacterial/fungal infections - don't use hydrocortisone without medical supervision since it can worsen or mask the disorder
- Camphor: dangerous if ingested, not for kids
- Don't use any product for more than 7 days
- Dosage form preference can also guide selections
30
Insect Bites Assessment
- Determine type of insect bite first
- Spider/tick - medical referral
- Serious reactions - medical referral
- Nonallergic reactions: appropriate for external analgesic for symptomatic relief and skin protectant to decrease irritation/inflammation is appropriate
31
Insect Bites Counseling
- Treating injury and preventing future bites
- Nondrug measures and proper use
- Include potential SE and signs/symptoms that require medical intervention
- Appropriate repellant use
32
Insect Bite Evaluation
- Follow-up: after 7 days of self treatment
- Seek medical attention if redness, itching, or swelling occurs during drug treatment
- Secondary infection, fever, joint pain, or lymph node enlargement are reasons to see a doctor
- Medical intervention if symptoms persist after 7 days
33
Insect Strings: Pathophysiology/Presentation
- Order Hymenoptera - bees, wasps, hornets, yellow jackets, and fire ants
- Attack victims to defend themselves or kill insects
- Inject venom with allergenic proteins and pharmacologic active molecules - varies between species
- Most complain of itching, pain, and irritation at site of sting with no systemic symptoms
- Allergic reactions: gives, itching, swelling, burning sensations, anaphylaxis (RARE, but can cause light-headedness, best tightness, drops in BP)
34
Wild Honeybees/Wasps/Hornets/Yellow Jackets
- Honeybees: West/Midwest, usually nest in tree trunks, stingers are barbed and stay in skin to keep injecting venom
- Paperhawks/Hornets/Yellow Jackets: South, central, and SW U.S., stingers aren't barbed allowing for multiple stings
- Paper wasps - nest in high places
- Hornets - nest in hollow places like trees
- Yellow Jackets - nest in low places like cracks in sidewalks or small shrubs, usual stinging culprits
35
Fire Ants
- Imported from South America, now in South/West U.S.
- Live in underground colonies with raised mounds
- Some only bite while others bite AND sting, bite is believed to cause reactions
- Can cause intense itching, burning, vesiculation, tissue necrosis, and anaphylaxis
36
Insect Sting Treatments
-Similar products for bites can be used for stings
37
Insect Sting Treatment Goals
- Relieve itching and pain of nonallergic reactions
| - Allergic reactions require medical referral
38
Insect Sting General Approach
- Remove stinger, apply ice pack (10 minutes intervals), apply local anesthetics, skin protectants, or counterirritants - appropriate when confined to site
- Avoid future stings to prevent allergy development
- Wear allergy bracelet or card to identify allergies if they have them
- Contact PCP for EpiPen script if allergies develop
39
Insect Sting Nonpharmacologic
- Ice pack, 10 minutes intervals, decrease absorption, itching, swelling, and pain
- Remove stinger/venom sac, preferably within 2-3 minutes so that venom isn't fully injected
- Scratch away stinger with fingernail or credit card
- Apply antiseptic after stinger is removed (hydrogen peroxide)
- Avoid attracting stinging insects: wear shoes, avoid perfume, bright clothes control food odors, change clothes if food gets onto it
40
Insect Stings Pharmacologic
- Same topicals as insect bites
| - Systemic antihistamines often used for sting itching, not indicated for it
41
Insect Sting Complementary Therapies
- Meat tenderizers - break down venom proteins
- Ammonia/baking soda - neutralize venoms
- Anecdotal success that may effect itching, efficacy not determined
42
Insect Sting Assessment
- Assess if allergic to venom
| - Refer to PCP if allergic reaction is occurring
43
Insect Sting - Counseling
- Reactions usually transient, but can become allergic with repeated exposure
- Epinephrine should be available to those who are allergic
- Nonallergic reactions should be recommended one or more topicals for symptom relief
- Advise about ASE and CI
44
Insect Sting - Evaluation
- Follow up within 7 days
- Seek medical attention if pain, itching, and local swelling worsens during treatment or if it persists after 7 days of treatment
- Secondary infection and fever should be referred to doctor
- Allergic reactions: follow up the same day
45
Pediculosis
- Lice and infestations in U.S. are common
| - 3 types: head lice, body lice, and pubic lice
46
Head Lice
- Most common, outbreaks usually happen in schools or day care centers
- Spreads with close personal contact or sharing personal items like caps, hairbrushes, and combs
- Peaks around August - November
- All socioeconomic groups effects
- Don't spread other diseases
- Infest head and live on scalp, lice egg or nit ~1 mm in diameter and found within 4 mm of scalp
- Once hatched, needs to feed within 24 hours else they die
- Matures into an adult within 8-9 days
- Without treatment, cycle repeats in 3 weeks
- Bites cause immediate wheals with papules appearing within 24 hours
- Itching/scratching can lead to secondary infections
- Nits/nit casings generally are spotted at the base of hair shafts, inspect the crown of head, near ears, and base of neck for these casings
- Firmly attached to nit/nit casings and their presence can indicate an infestation
47
Body Lice
- "Cooties," live, hide, and lay eggs in clothing
- Periodically attach to body for blood feeding and can transmit typhus and trench fever
- Usually occur in those who don't shower or change clothes regularly, like the homeless
48
Public Lice
- AKA crabs, usually spread from sexual contact
- Can also spread from toilet seats, sharing underwear, or bedding
- Can also infect armpits, eyelashes, mustaches, beards, and eyebrows
49
Lice Treatment
- Non-Rx pediculicide agents
- Hair combing for nit removal
- Home vacuuming and cleaning or personal items
50
Lice Treatment Goals
- Killing adult/nymph lice
| - Removing nits from patient's hair
51
Lice General Treatment
- Pediculicide on infected body area
- Hair combing
- Avoidance of future infestations
52
Lice Nonpharmacologic
- Careful visual inspection with nit comb, like LiceMeister comb, to remove nits are helpful for treating/controlling lice
- Avoid contact with infested individual
- Wash clothing/bedding with hot water and dry in dryer to kill lice/nits
- May also seal in plastic bag for 2 weeks
- Hairbrushes/combs - wash in hot water
- Vacuum carpets, rugs, furniture regularly and thoroughly
- May also shave head to help get rid of lice
- Body lice: appropriate body hygiene and frequent changing/laundering of clothes/linens
53
Lice Pharmacologic
- Permethrins or synergized pyrethrins
- Don't overuse due to increasing resistance
- Resistance due to overuse, improper use, or insufficient contact times can occur
54
Synergized Pyrethrins
- Approved for head/public lice
- Add a piperonyl butoxide
- Block nerve impulse transmission leads to insect paralysis and death
- Piperonyl butoxide: inhibits pyrethrin breakdown with increases insecticide concentrations
- Excessive contact can increase systemic absorption
- Pyrethrins: 0.17-0.33% + Piperonyl Butoxide: 2-4%
- Effected pediculicide topically as a shampoo, foam, solution, of gel
- AAA for 10 minutes, then rinse/shampoo as recommended
- Comb following treatment
- Repeat in 7-10 days to kill remaining nits that have hatched
- Don't apply more than twice per 24 hours
- Low toxicity when applied correctly
- ASE: irritation, erythema, itching, swelling
- Avoid eye and mucus membrane contact
- Avoid if allergic to pyrethrins, chrysanthemums, or ragweed (cross sensitivity)
55
Permethrin
- Synthetic pyrethroid for non-Rx cream rinse for head lice ONLY
- Act on nerve cell membrane, disrupts sodium channels, leads to paralysis and death
- When applied, <2% absorbed systemically which is then metabolized
- 1% cream rinse should be applied in sufficient quantity to cover/saturate washed hair and scalp
- Leave on for 10 minutes then rinse and comb with lice comb
- Treatment has a residual effect for up to 10 days, so 2nd wash isn't necessary
- ASE: pruritis, burning, stinging, scalp irritation occurs in 10% of population
- Avoid eye and mucus membrane contact
- CI: hypersensitivity to pyrethrins/chrysanthemums, don't use in less than 2 months
56
Lice - Pharmacotherapeutic Comparison
- Single application: permethrin is more effective
| - Two applications: no significant difference in efficacy between the products
57
Lice Product Selection Guidelines
- Pyrethrins: 2 y.o. or older, used in preggo and BF only if prescribed by doctor, may be recommended for public lice too
- Can use either for head lice based on preference of dosage forms, allergies, and desire for single applications or not
58
Lice Complementary Therapies
- Lice enzyme shampoos, breakdown lice exoskeleton
- Product with 10% tea tree oil and 1% lavender oil application
- Application every week for 3 weeks was found to be more effective than non-Rx applied twice
- Tea tree oil: use with caution due to allergic reaction and possible toxicity
- Other oil based products like petrolatum and mayonnaise are also used to impair respiration, but no effective and likely just to slow them down
- Avoid using gasoline or kerosene
59
Lice Emerging Therapies
- DSP lotions (Cetaphil): new product study, nontoxic lotion that "shrink wraps" lice
- Applied to hair and dried with hair dryer, cover breathing holes and suffocates louse
- Dimethicone 4% lotion: cures pediculosis and causes less irritation, coats lice and immobilizes them within 5 minutes of application
- LouseBuster applies heat to hair/scalp which dehydrates lice/nits leading to their death
- Kills ~90% or more of nits, but expensive and requires technician to operate the machine
60
Lice Assessment
- Visual inspection of scalp
- Body lice: identifying adult lice in clothing seams
- Don't recommend pediculicide in those without inspection confirmation
- Recommend pediculicide once inspection confirms lice infestation
61
Lice Counseling
- Pharm + nonpharm interactions needed
- Head lice isn't from poor hygiene
- Discuss products, proper use, and preventable measures
62
Lice Evaluation
- Follow up: 10 days
- If signs of infestation persist after pediculicide treatment, refer to PCP
- Discourage overuse of pediculicide and emphasize nonpharmacologic measures
