Bites, Stings And Infestations Flashcards
Nerovascular exam
1st step in management of a sting/bite/infection
- make sure to check parenthesis, alertness and ability to move
- make sure to also look for bone and joint involvement as this indicates a worsening condition*
Tetanus toxoid vs tetanus immunoglobulin
- during the management of a bite/sting or infestation, make sure to check last tetanus injection*
toxoid must be given if:
- last vaccine was > 10 yrs (clean wound)
- last vaccine was > 5 yrs (dirty wound)
Immunoglobulin must be given if less than 3 full doses of a tetanus vaccine in patient history
Rabies prevention and antibiotic use
Rabies:
- must give immunoglobulin and vaccine if no prior vaccine has ever been given.
- only have to give vaccine if previous vaccine series has been given
Antibiotics:
- specific for certain bacteria and typically oral medications
- most common prescribed is amoxicillin-clavulonic acid orally*
- IV is indicated with bone/joint/ serious tissue damage
When to close bite/sting wounds
Facial wounds must always be closed
- NEVER CLOSE HAND/FEET WOUNDS*
- poor circulation so would just result in pus filled hypoxia
Try to not close cat or human bites and only close superficial dog bites
Broad criteria for closure:
- uninflected at time
- < 24 hrs old
- not on hand/foot
- not immunocompromised
Human bites overview
Breast bites are to be assumed sexual assault until proven otherwise
Arm bites > 2.5 cm in diameter on children are assumed to be child abuse until proven otherwise
2 categories of human bites:
clenched fist injuries
- typically result from fights and usually at 3-4th fingers
- need antibiotics and might need to operative treatment if fever and extreme swelling are present
occlusive bites (closing mouth around the skin) - need antibiotics and most commonly caused by children
Elkinella corrodens
Unique pathogen to human bites only
Causes blood culture-negative endocarditis
- infection rate is 30%
- resistant to most antibiotics and has to be treated with amoxicillin-clavuloinic acid
staph and step are also possible human bite pathogens
Cat bites overview
Most common in women and typically hand or feet
80% of cat bites lead to infection and usually within 24 hrs of bite
- narrow penetrating wounds increases chances of infection
- marked by really small bite marks, but extreme swelling of the bite area*
Usually require xrays to evaluate for teeth, joint or bone involvement
Most common symptom outside of swelling is cellulitis
Pasteurella multocida
Unique pathogen to cat bites and has a 30% mortality rate
Results in osteomyelitis and joint abscess if left untreated
- can also result in tenosynovits which requires 100% surgery
Treatment:
- amoxicillin-clavulonic acid
Cat scratch fever
Caused by Bartonella henselae infections
- caused by flea feeces under cat nails/ around their teeth
- cardinal sign is fever with gigantic sentinel lymph nodes to site of infection
DO NOT CUT OPEN OR DRAIN LYMPH NODE
- prescribe antibiotics (which don’t actually help, just prevents other possible opportunistic pathogens) and let the body heal itself
Dog bite overview
Most common in males 5-9 years
- children - face/neck
- adults = arm/ leg
Much more dangerous since dogs apply more pressure and tear rather than puncture
- causes of death include carotid avulsion (throat bite), skull injuries/Brian injuries and mengitits
- can also cause compartment syndrome due to increase pressure and accompanying rhabdomyolysis
Infection rate is 30%
Dog bites almost always are indicated for xrays
Capnocytophaga canimorsus
Pathogen unique to dogs
- 30% mortality rate and much higher chance in immunocompromised
Fight bite injuries specifics
Should include imaging and labs to R/O tenosynovits/osteomyelitis and septic arthritis
Most common infectious agents are Elkinella corrodens and staph aureus
Viper snake bites
Toxic snake bites that produce cytotoxic effects
Include rattlers copperheads and pit vipers
Pit viper bites can be dry bites (25%)
Symptoms:
- oozing pus at bite site
- cell injury signs (swelling ecchymoses, blackening necrosis)
- systemic signs: fatigue, headache, DIC, fasciculations
- can develop IgE mediated anaphylaxis due to type 1 sensitivity
Almost all infections are gram-negative infections
TREATMENT:
- antivenin ASAP ( especially if progression of injury, coagulpathy or systemic effects kick in)
- DO NOT USE TOURNIQUETS OR SUCK VENOM OUT
Elapid snake bites
Include coral snakes, spitting cobra and black mamba
Presents with neurotoxic effects
- most common is ACh receptors bind irreversibly.
Most common in fingers
Symptoms:
- parasthesia, double-vision, dysphasia, aphasia, muscle weakness/CNS dysfunction
- Death almost always occurs via respiratory failure*
Treatment:
- antivenin if neurological symptoms present
- if not severe neurological symptoms, supportive care is indicated
Characteristics of venomous vs non-venomous snakes
Non venomous:
- red on black: venom lack
- rounded head w/ rounded pupil
- NO FANGS
- double row of subcaudal plates
Venomous:
- red on yellow: kill a fellow
- triangle-shaped head w/ elliptical pupil
- FANGS
- single row of subcaudal plates and/or rattle
Brown recluse/ hobo spider
Common spider bite that live in woodpiles/cellars (reclusive areas)
Asymptomatic initially but will develop “volcanic “ lesions if untreated.
this leads to ischemic necrosis, hemolysis and thrombocytopenia w/ renal failure within days
Treatment:
- NO ICE
- treat with hyperbaric chamber and surgical debridement
- can use dapsone, unless patient has G6PD (will cause hemolysis)
Black widow
Common spider bite that mostly occurs within woodpiles/ dumps
- can occur anywhere though since black widows are far more aggressive than brown recluses
Effects are caused by latrotxin
- destabilizes neuronal membranes and forcibly permanently opens sodium channels, which causes chronic depletion of ACh into synapse
Symptoms:
- immediate pain at lesion site
- abdominal cramps that mimic appendicitis
- vomiting
- nausea
- cardiac arrthymias
Treatment:
- ice and pain medications w/ calcium gluconate if mild symptoms/ healthy
- benzodiazepines Intravenously with antivenin if extreme symptoms are present/ old or child
Scorpions
Only species that is dangerous is bark scorpion
- usually found under rocks/ logs or floors
C. Sculpturatus venom stings
- neurotoxin that causes repetitive firing of axons by chronic unregulated sodium channel activation
Symptoms:
- immediate pain at site
- local = edema, erythema and “jump sign” when touched
- systemic = very large erythema are, anxiety, spasms, nausea, strange eye movements
Treatment:
- Ice and pain medication via opiate usually if mild/healthy
- antivenin with IV benzodiazepines if extreme symptoms/old or young
- in both cases can prescribe nitroprusside for control of HTN*
Bees/ wasps/ fire ants (Hymenoptera)
Toxicity is not caused by venom, but rather by bodies systemic reaction to the venom
Symptoms:
- local = Irritation, itching, redness, swelling, immediate pain
- systemic (allergic) =
IgE mediated (most common cause of death)
Cardiovascular collapse, ischemia and shock
Can result in serum sickness after treatment
Can result in delayed systemic toxicity after 24 hrs from exposure.
- causes multi-organ failure
Treatment:
Ice and pain meds
- IV corticosteroids, NSAIDs
- IV antihistamines if allergic reaction
Marine animals
Includes jellyfish, stingrays and sea urchins
- MOST dangerous = box jellyfish*
- causes respiratory arrest
Treatment:
- MUST remove stinger
- DO NOT PEE ON OR SCRUB THE WOUND
- immerse in hot water w/ vinger if pain is extreme
- can use topical lidocaine as well
- if stingray stinger causes lacerations, must repair and treat antibiotics*
- not doing so results in necrotizing facilities and sepsis, which would be treated with tetracycline and ciprofloxacin
Scabies
Caused by mites that burrow in skin and lay eggs
- identified via magnifying glass
Results in pus filled lesions that can be confused with impetigo or atopic dermatitis
Treatment:
- permethrin cream
- lindane (EXCEPT in young since its neurotoxic)
- require fumigation of house to prevent recurrence
Bed bugs
Feed off blood and cause red itch non-pus filled papules
- often confused with mosquito bites, hives or eczema
Treatment:
- wash self and fumigate house
- toss all bedding and clothes infected
Mites
Transmitted via ticks and results in rickettsialpox reactions
- rash occurs at site of bites and often resembles chicken pox
- rash looks firm, red/black papular lesions
Symptoms
- fever, chills, headache
- swollen lymph nodes (not anywhere close to cat scratch size though)
- rash, myalgia, sweating
Treatment:
- remove mites and fumigate house
Carpet beatles
Everything is similar to bed bugs except they caused rash via movement on you, NOT BITING
Rash is much more systemic and is intensely pruitic and can become bulbous
Treatment:
- fumigate house and clean self
- same as bed pugs
Fleas
Bites them selves do not do anything.
- symptoms arise from hypersensitivity to them and complications to scratching them
- scratching bites causes secondary infections usually via staph aureus*
Rash is similar to lice mites and scabies except can be hemorrhagic
- most common sites are ankles and waist line*
Treatment:
- prevent by treating pets and fumigating house
-
Head lice
Most common sites are scalp, body and gentialia hair
- most common infestation and almost exclusively in children 3-12 yrs*
Symptoms:
- intense purity’s of area, red Macules
- looks lie dermatitis and eczema/ scabies
Diagnosis: must ID lice on hair shafts (look like grains of rise)
Treatment:
- permethrin shampoo (initially and then 1 week after 1st treatment)
- MUST REMOVE ALL AND NO NEED TO FUMIGATE
- Not suppose to recommend missing school
Is pregnancy a contraindication of antivenin?
No
