1- Insect Bites and Stings Flashcards
What insect obtain blood from host directly?
mosquito, bed bugs, lice
What insects obtain blood from host indirectly?
ticks, horse flies, biting midges
What is the local reaction created by mosquitos?
wheal-and-flare response peaks in ~ 20 minutes, indurated pruritic papule peaking in 2-3 days
What diseases may be transmitted through mosquitos?
in the United States= west nile, zika, chikungunya BUT worldwide= malaria, yellow fever, dengue
HIV is NOT spread through mosquitos
What is the local reaction caused by ticks?
itchy papules (disappears in 1 week)
What possible systemic reaction can occur via tick bites?
red meat allergy (alpha-gal allergy)- most associated with the lone star tick in US and possible tick paralysis after tick feeding for 4-7 days
Where are mosquitos found in nature?
around standing water
What disease may be transmitted through ticks?
lymes disease, rocky mountain spotted fever
Where are ticks found in nature?
wooded areas
What is the local reaction caused by fleas?
papules arranged in non follicular pattern (multiple and grouped) and can produce significant urticaria
What disease my be transmitted by fleas?
bubonic plague and endemic typhus
Where are fleas found in nature?
on/around wild mammals
What is the local reaction caused by scabies?
inflammation and intense itching usually found in folds in the body
Where are scabies found in nature?
humans, usually transmitted by physical contact
What is the local reaction caused by bedbugs?
exposed skin (head, neck, arms) found in cluster of two or threes in a straight line
Where are bedbugs found?
crevices of walls, floors, picture frames, bedding, linens during the day, but come out and cause bites at night
Venomous
toxin administered by biting (injected)
Poisonous
toxin administered when eaten (secreted)
Toxin
biologic substance that impacts biological function in other organisms
What are the goals of treatment of bug bites?
relieve symptoms and prevent secondary bacterial infection
What are the exclusions for self-care of bug bites?
-hypersensitivity to insect bites, resulting in systemic symptoms or symptoms away from bite area
- < 2 years of age
-history of tick bite and systemic effects indicating possible infection
-suspected spider bite requiring medical attention
-signs of secondary infection of bite area
What are some tips for patients to avoid insects?
-cover skin and cuff around ankles, wrists, and neck
-keep pets free of pests
-avoid standing water
-use barriers such as screens and netting
-avoid outdoors at dawn and dusk
-avoid contact with infected individuals
What pests do insect repellant repel?
mosquitoes, fleas, ticks
What concentration of DEET is recommended for children?
<30%
What is the minimum effective dose of DEET to prevent tick bites?
20%
What are adverse effects of DEET?
-shin rashes or eruptions
-if ingested, CNS reactions (seizures, ataxia, hypotension)
What is the indication of local anesthetics for bug bites?
relief of itching and irritation
What products are local anesthetics?
benzocaine, pramoxine, benzyl alcohol, lidocaine, dibucaine, and phenol
What is the MOA of local anesthetics?
reversible blockade of conduction of nerve impulses at the site of application
How should local anesthetics be applied?
apply to bite are 3-4 times a day for NO LONGER than 7 days
What are the adverse effects of local anesthetics?
relatively low systemic absorption, may cause allergic contact dermatitis
What is the indication of topical antihistamines?
pain and itching
What products are topical antihistamines?
diphenhydramine hydrochloride 0.5-2%
What is the MOA of topical antihistamines?
depresses cutaneous receptors
How should topical antihistamines be applied?
3-4 times daily for NO LONGER than 7 days
What are the adverse effects of topical antihistamines?
photosensitivity and hypersensitivity, continued use increase risk of contact dermatitis
What is the indication for counterirritants?
itching and irritation
What products are counterirritants?
camphor, menthol
What is the MOA of counterirritants?
depress cutaneous receptors
How should counterirritants be applied?
3-4 times daily for up to 7 days
What products are skin protectants?
zinc oxide, calamine, titanium oxide
What is the indication of skin protectants?
inflammation and irritation, zinc is a mild astringent and has weak antiseptic properties
What is the difference between a honeybee and wasp/hornet/yellow jacket sting?
-honeybee has a barbed stinger which remains embedded
-W/H/yellow jacket may remove their stinger and sting repeatedly
What is the effect of a fire ant bite?
intense itching, burning, and potentially tissue necrosis
What are the exclusion for self care of a sting?
-hives, excessive swelling, dizziness, weakness, nausea, vomiting, difficulty breathing
-significant allergic response away from the sting
-previous sting by honeybee, wasp, or hornet
-previous severe reaction to insect bites
-person or family history of significant allergic reaction
-< 2 yo
How can cold packs be used for stings?
apply to site of sting in 10 minute intervals to slow absorption and reduce itching, swelling, and pain
What complementary therapy can be used for stings?
-meat tenderizer= breaks down venom
-ammonia and baking soda= neutralize venom in bites
