Bites, Burns, Wounds Flashcards
Insect bites/stings pathophys
Various bugs may bite (e.g., spiders and ticks), sting
(e.g., bees and ants), or emit toxic secretions (e.g.,
caterpillars).
Most commonly, these injuries are self-limiting skin
reactions (i.e., inflammation).
Occasionally, serious systemic effects may occur,
leading to anaphylaxis or transmission of disease.
In North America, deaths are rare
what are some common types of bites
spiders, ticks, mosquitoes, bed bugs
spider bites
Spiders rarely bite humans. Some are venomous
(e.g., black-widows, brown recluse), but most do
not result in systemic symptoms that would require
hospitalization. Those that do may cause
progressive symptoms from sweating and nausea
to tissue necrosis.
tick bites
- Ticks attach to warmer areas of the body (e.g.,
armpit, groin, scalp) and feed on blood. - Common reactions include redness and swelling
- Ticks infected with Borrelia burgdoferi may cause Lyme disease, which begins as a bull’s-eye rash and can progress from flu-like symptoms to cardiac and neurological complications.
- May transmit from animals.
mosquito bites
- Salivary secretions from the female mosquito cause local histamine reactions that typically result in red, itchy papules.
- Many viral and parasitic infections may be transmitted by mosquitoes including malaria, West Nile, and zika, therefore prevention of bites is key
bed bugs
- Bugs are typically found near mattress and boxspring seams.
- They often bite the arms and legs in clusters of 3-5, resulting in red, itchy lesions.
- Unlike lice, they may live up to a year without feeding. - Professional chemical extermination or application of heat and other measures are necessary for eradication
- not known to spread disease
stinging insects - which 3 insect families
- Three insect families known to cause reactions
are bees, vespids, and stinging ants - In those who are susceptible, venom causes local
inflammatory reactions (within 4-48 hours), or
over a larger area (subsiding over 3-10 days) - Systemic reactions are more likely with multiple stings
red flags for bites and stings
consider normal presentaiton
- localized rxns s (itching, redness, swelling)
- mild allergic rxns (hives, rash, swelling)
use topical management
- <2 years of age - pro judgement
- extensive local rxn ? 10 cm in diameter persisting several days
- multiples bites/stings
- sting to mouth, tongue
- history of rxn to previous bites/stings (anaphylaxis)
- immunocompromised and lesion remains after 7 days with no improvement
bites and stings goals of therapy (4)
Prevent bites and stings
Prevent diseases or reactions caused by bites and
stings
Ensure patient receives appropriate care when
warranted (In the case of more serious reactions)
Provide symptomatic relief of localized reactions
bites and stings prevention
- Avoid using scented products
- Cover skin as much as possible (Clothing should be tight at wrists / ankles)
- Avoid tall grasses or standing water
- Limit time spent outside at dawn / dusk
- Avoid / use caution when eating outdoors
-Use mosquito netting, especially for infants <6 months
of age and for travelers. - Avoid situations where insects may feel threatened (i.e. nests)
bed bugs prevention
New environments (e.g., hotel rooms) should be
carefully checked
Examine seams of mattresses, behind headboards,
under baseboards and in curtains for infestation.
Bugs can also sometimes be seen before dawn when they are most active and slower-moving from feeding
Insect repellents have not been shown to be effective for preventing bed bug bites.
insect repellents
examples?
Can deter biting insects, but not stinging ones
Should be applied directly to clothing / exposed skin in ventilated area
Products containing a Pest Control Product (PCP) registration number on the label
should be chosen.
Can be used in pregnancy and breastfeeding with the exception of citronella
- avoid spraying onto face/near eyes/mouth, hands of small children
- not used in children <6 mos
examples
DEET (N,N-diethyl-m-toluamide) - offensive smell,
- low conc for greater than 6 mos, high conc older than 12
PMD (P-menthane 3,8-doil)
- MOA unknown, under age of 3
Icaridin / Picaridin
- conceals attractants, changes ability of bugs to smell
Oil of citronella
- offensive taste of smell, not for under 2
Soybean oil
- all ages safe, conceal attractants, cools skin surface temp
non-pharm treatment for stinging insects
For stinging insects:
Remove stinger to stop injection of venom and decrease local reaction. Remove with tweezers, finger nails or credit card.
Cleanse area with soap and water to prevent secondary infection.
Use cold compresses to provide relief and reduce swelling.
Methods such as applying toothpaste or vinegar may help with symptoms, but have not been studied.
For ticks:
Remove using tweezers. Grasp as close to the skin as possible and avoid twisting (head may remain in skin).
Cleanse area with soap and water to decrease local irritation.
Methods such as applying petroleum jelly or burning off with alcohol and matches (?!) have no proven efficacy or may damage skin.
Name 6 types of pharm treatments for bites/stings
analgesics antihistamines astringents/protectants anesthetics counterirritants corticosteroids other (ammonia/baking soda After Bite) - local cooling and anti-pruritic
Analgesics for bites and stings
e.g., acetaminophen, ibuprofen
Typically in oral dosage forms
Suggest typical doses
antihistamines for bites and stings
first-generation (Benadryl® - diphenhydramine, Chlor-Tripolon® - chlorpheniramine)
- more side fx, drowsy, shorter duration of action
second-generation (Reactine® - cetirizine, Claritin® loratadine)
Both are equally effective
Oral > topical due to risk of contact dermatitis
First-gen cause more sedation and have a shorter DOA
Second-gen are more expensive but also more convenient
Astringents / Protectants for bites and stings
e.g., calamine, zinc oxide
Well tolerated, but cosmetically less appealing, leave a pink/white film
soothe skin
anaesthetics for bites and stings
e.g., benzocaine, lidocaine, pramoxine
Reduce nerve impulses on the skin
Offer only minor relief and have a short DOA
Remember, these are known sensitizers
Counterirritants for bites and stings
Counterirritants
e.g., camphor or menthol
Offer cooling, pain-relieving, anti-pruritic effects
lacks evidence, can cause more irritation later on
Corticosteroids for bites and stings
e.g., hydrocortisone 0.5% or 1%
May relieve itch associated with local reactions
4 times a day for max 7 days - no prescription unless children under 2 - need Rx
Anaphylaxis
symptoms?
what is the first line treatment? how are they used?
may occur minutes to hours after allergen exposure
Respiratory – coughing, throat tightness, tongue swelling
Cutaneous – hives, itching, flushing
GI – nausea/vomiting, cramping
Other – lightheadedness, sweating, panic
First-line treatment is administration of epinephrine.
Decreases bronchospasm, enhances blood flow and blood pressure. Patients should go to the emergency department after administration of epinephrine, as some reactions are biphasic (could recur after a few
hours).
NB: Oral antihistamines are second-line for hives/itching
Epi pens
- schedule 2
- go straight to emergency room after 1st dose
- 2nd dose used 5-15 minutes if there was inadequate response
- Jr for b/w 15 to 30 kg
Monitoring and Follow-Up
provide timelines for: pain and fever itching swelling/redness local infection suspected anaphylaxis
In most cases, symptoms should be “eliminated” or “reduced a level acceptable to the patient.”
Pain and fever
Pain should subside in 24 hours
Fever , if present, should subside within 7 days
Itching
Monitor daily and with each application/dose of treatment
Should subside within 7 days
Swelling / redness
Increase or worsening
Should normally subside within 24-28 hours
Local infection
Swelling, redness, tenderness, pus, fever
Monitor for up to 7 days after exposure
Suspected anaphylaxis
Monitor for s/sx within at least 30 minutes of exposure
Burns pathophys
causes?
factors determining severity?
Burns encompass a spectrum of tissue injuries that result in local and systemic responses.
They may result from a number of causes:
Heat (e.g., flame; hot liquids, gases, or objects; smoke)
Radiation (e.g., the sun / UV rays, lasers)
Electricity (e.g., appliances)
Chemicals (e.g., cleaners)
Burn severity is related to several factors:
Body location / skin thickness
Cause of the burn and duration of exposure
Extent (surface area affected) and depth of burn
what are the types of burn?
1st degree 2nd degree (superficial partial thickness) 2nd degree (deep partial thickness) 3rd degree (full thickness)
1st degree burns
location, cause, presentation, time for healing?
Affect the epidermis only
Causes: sunburn, low-intensity heat
Presentation: dry, pink, blanches with pressure,
some pain but no edema, skin remains intact
Healing: 3-7 days without scarring
2nd degree (superficial partial thickness)
location, cause, presentation, time for healing?
Affect the epidermis and upper dermis
Causes: scalds, flame, dilute chemicals
Presentation: moist, weeping, blanches with
pressure, extreme pain, small blisters
Healing:3-7 days, some pigment changes,
generally no scarring
2nd degree (deep partial thickness)
location, cause, presentation, time for healing?
Affects the epidermis and deep dermis, including hair
follicles and sweat glands
Causes: scalds, oil/grease, flame, prolonged
exposure to dilute chemicals
Presentation: wet/waxy or dry, variable color (red/white), blisters, no blanching with pressure, pain only with pressure
Healing: >21 days with possible scarring and contractures (tightening of tendons/muscles)
3rd degree (full thickness)
location, cause, presentation, time for healing?
Affects the epidermis, dermis, and subcutaneous layer
Causes: immersion/scalding, concentrated chemicals,
electricity
Presentation: dry/waxy, to charred and black, no
blanching with pressure, painless (Why?)
Healing: requires intervention (e.g., surgery, grafts), high risk of fluid loss, infection, scarring, and contractures
Name 3 complications wtih burns
Name 5 factors that increase risk of infection
Infection
Fluid / electrolyte imbalance
Scarring
factors
Medical conditions like diabetes or vascular diseases
Age (<5 or >60 due to probable skin thinness)
Immunosuppressive drug therapy
Malnutrition
Smoking
red flags for burns
- refer for deep partial-thickness or full-thickness burns
Referral is warranted in the following situations:
>10% TBSA for adults or >5% TBSA for children
Any size of burn that is more serious*
Any burn involving thin skinned areas or individuals
presumed to have thin skin (face, ear, eyelid)
Burns on hands/feet or circumferential burns (circumference of digit/extremity/torso)
Concomitant trauma (e.g., electrocution)
Chemical burns (may progress), electric or inhalation burn
Possible inhalation injury - < 5y or >60 y
- monitor if there is underlying medical condition that can delay healing
Non-pharm/first aid for burns
Remove the patient from the causative agent
Cool by applying cool tap water
Reduces pain, inflammation, and tissue damage
Remove jewelry or other restrictive items in case of swelling
Clean any secretions or debris with mild soap and tap water
Leave blisters intact; if they break, gently clean
Cover with non-adherent gauze dressing - [rotects from friction and contamination
Avoid antiseptics or disinfectants - may impair healing
Pharm for burns
Antibacterial Agents
Poor evidence
Topical antibiotics (e.g., Polysporin®) not recommended unless an infection is present
Silver sulfadiazine (Flamazine® - Rx) historically used, but newer dressing options may lead to better healing outcomes
Pharm for burns
Analgesics
Usual doses of acetaminophen or ibuprofen (or opioids)
Avoid ASA, as may promote bleeding from deep wounds
Lidocaine/benzocaine/pramoxine often marketed for burns, but little evidence for use and may sensitize
Camphor/menthol/phenol could have cooling effect, but also little evidence for use
Antipruritics
Itch is common during healing phase
Colloidal oatmeal (Aveeno® products) and other topical moisturizing products may provide symptom relief
Oral diphenhydramine (Benadryl®, cetirizine (Reactine®), or hydroxyzine (Atarax® - Rx), may be beneficial if itching is bothersome
other pharm options for burns (4)
Suggest the use of sunscreen as burned skin is susceptible to damage
Honey – anti-microbial and anti-inflammatory properties may improve healing by 4-5 days
Aloe vera – inconclusive evidence, may cause some irritation
Tetanus vaccine – for partial- or full-thickness burns
Monitoring and Follow-Up
4 things to look out for
Pain
Every 4-6 hours initially, then daily
Use a pain scale (0 no pain 10 worst pain)
Itching
Every 4-6 hours initially, then daily
Burn healing
Every 2-3 days initially, then weekly
Infection
Daily at dressing changes
Consider swelling, redness, pus, fever, etc
wounds pathophys
Wounds occur due to mechanical trauma that disrupts normal skin structure and functioning
May be of partial- or full-thickness
Affecting the epidermis and dermal layers, or penetrating to subcutaneous tissue and exposing fat, muscle, or bone.
May be acute or chronic
Acute wounds include bites, burns, scrapes, and minor surgical procedures; they usually heal within 3 weeks.
Chronic wounds occur due to delayed or impaired healing and are beyond the scope of this lecture
e.g., pressure ulcers, diabetic foot infections
what conditions are needed for healing of wounds? (4)
name 4 healing phases
regenerate/repair skin - scar tissue
conditions
Well vascularized
Clear of infection
Free of necrotic tissue - may harbor bacteria
Moist - accelerates epidermal migration and dermal repair
Wound healing involves 4 phases
1. Hemostasis phase – begins within minutes, release of inflammatory mediators assists with clot formation, etc.
2. Inflammatory phase – lasting ~4 days, WBC migration prevents infection
and begins repair process.
3. Maturation phase – also within 4-5 days, collagen forms early scar tissue to close and strengthen the wound.
4. Proliferative phase – lasting ~24 days, the wound remains red and raised but starts contracting.
- collagen can continue to strengthen the wound for up to 2 years depending on the type of wound
complications with wounds - infection
Minor infections
Redness, tenderness, warmth, discharge
Major infections
Discharge, odor, delayed healing, increased pain
Wound factors that may increase risk:
Foreign matter in the wound
Location of the wound (exposure to contamination)
Depth of wound and involvement of other tissues
Presence of devitalized tissue
Patient factors that may increase risk:
Age (thinner skin delays healing process)
Underlying medical conditions (e.g., diabetes)
Extremes of body weight (poor nutrition)
Smoking (decreased blood flow to area)
Drug therapies (e.g., that affect immunity or clotting)
complications with wounds - swelling
Occurs when collagen and glycoprotein deposit at the wound site.
Moist healing environments decrease the extent of scarring by accelerating the phases of repair.
Discoloration of the area can occur, but this may be
minimized by using sunblock for ~6 months while the wound is healing.
Darker the skin type, the more likely the body is to form a thicker scar. Believed to be caused by genetics, skin coloring, and the area of the body (i.e. earlobes)
Options exist for preventing scar formation or minimizing existing scars. e.g., silicone gels
red flags for wounds
Wounds that continue to bleed despite application of
pressure:
Wounds that expose fat, muscle, or bone
Visible foreign material despite irrigation
Gaping / large wounds (>2cm)
Deep puncture wounds
Wounds from animal bites
Wounds causing severe pain
Chronic wounds or those at risk of delayed healing due to wound / patient factors
Signs of infection
goals of therapy for wounds (4)
Optimize wound healing and prevent deformity
Prevent infection
Minimize further trauma
Minimize patient discomfort
non pharm treatment for wounds (3)
Cleanse the wound
Once obvious debris is removed, cleanse with water (just as effective as normal saline). If any debris remains, it may be removed with tweezers or brushed away with gauze (if reasonable to do so!).
Stop any bleeding
Apply dressing or gauze for 10 minutes. Those on
anticoagulants may take ~15 minutes.
Apply a dressing
Choose a dressing that maintains moisture
Minor wounds may be closed with a Band-Aid® or liquid bandage. Major wounds that are gaping, deep, or jagged may require stitches
pharm for wounds
Cleansing and antiseptic agents
Normal saline, distilled water
Fine to use; may not be necessary
e.g., hydrogen peroxide 3%, isopropyl alcohol 70%,
iodine
In general, avoid direct application to the open wound. Most of these measures are irritating and potentially cytotoxic. Unless there is a high risk of infection, encourage plain water (and mild soaps).
pharm for wounds
Topical Antibacterials
Prophylaxis – generally not recommended unless there is a high risk of infection
Treatment – for superficial, mildly infected wounds
e.g., Polysporin® cream or ointment – OTC
e.g., fucidin acid (Fucidin® - Rx) or mupirocin (Bactroban® - Rx)
All are applied BID to TID, may cause localized irritation
Should be used only as long as is necessary
pharm for wounds
Oral Antibiotics
Indicated for human/animal bites, deep wounds, or those persisting >2 weeks despite proper care
monitoring (3 parameters)
Bleeding
Should stop within 10 minutes
- 15 for immunocompromised pts
Infection
Monitor daily at dressing changes
Wound healing
Monitor daily for 4-14 days
