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
