BITER ALERT!!!! Love, Dr. Parker

BITER ALERT!!!! Love, Dr. Parker

(Management of bites and stings)

DOG BITES

• What bugs to cover?

• Other management

Multiple Select

What organisms would you cover for a dog bite?

• Pasteurella multocida

• Staph aureus

• COVID 19

• Cocci

• None of the above, a dog's mouth is bacteria-free.

EWWWWW

• 28 species of aerobic and 12 species of anaerobic organisms can be isolated from dog bites!

Multiple Select

Which antibiotics would you choose?

• Clindamycin AND Bactrim

• Augmentin

• Doxycycline

• Clindamycin AND Fluoroquinolone

• None of the above, a dog's mouth is squeky clean

Bugs and Drugs

• Pasteurella multocida and Staph aureus

• 7–10 day antibiotic course

• Augmentin—good first choice.

  •Daily ceftriaxone IM can also be considered.

• PCN allergic:

  •Doxycycline (not children < 8 and not pregnant patients)

  •Adults:

  •clindamycin AND fluoroquinolone

  •Children:

  clindamycin AND trimethroprim-sulfamethoxazole

Admit to hospital with IV antibiotics if:

• Fail outpatient treatment

• Systemic signs of infection: fever/chills

• Severe, spreading cellulitis or cellulitis over a joint

• Bone, joint, nerve, or tendon involvement

Dog Bite mgmt In a nutshell:

• Wound inspection of deeper structures

• Control hemorrhage

• Meticulous wound care

• Decision regarding primary closure (consider if wound uninfected and on the face and for hemostasis)

• Prophylactic antibiotics

• Tetanus and rabies prophylaxis

Cats, ugh.

What to do when they bite (aside from euthanasia)

Fill in the Blank

When thinking of cat bites, which organism comes to mind?

Bartonella Henselae...remember?

• Cats carry bacteria in erythrocytes... 

  •Which then contaminate saliva when biting

  •Fleas horizontal vector to cats and to humans

EWWWW

• Bite from infected cat:

  •Vesicles at the original site

  •2 weeks later regional lymphadenopathy (usually ipsilateral)

• Can persist for several months!!

• Think about fever of unknown origin in kids! 

Management

• Can obtain Titers

  •IgG >1:256 suggest active infection

• Azithromycin

  May shorten duration of lymphadenopathy

• Board question: Bacillary angiomatosis and peliosis (liver dissemination in immunocompromised person)

Bacillary Angiomatosis

• Bacillary angiomatosis is also known as epithelioid angiomatosis is an uncommon disease and is a disorder characterized by neovascular proliferation in the skin or the internal organs and presenting as tumor-like masses due to infection with Bartonella henselae or Bartonella quintana.

• Originally, bacillary angiomatosis was described in HIV patients but is known to occur in other non-HIV immunocompromised states as well as in immunocompetent persons.

• BA was first described in 1983 as an atypical subcutaneous infection associated with AIDS (Acquired immunodeficiency syndrome).

Peliosis

• The neovascular proliferative lesions in the internal organs are known as peliosis and are common in liver and spleen.

Bacillary Angiomatosis

Human bites....

"Trust no one"

Typical mouth flora

• Eikenella corrodens

  •Gram-negative anaerobe found in human mouth

  •Approximately 30% of human bites

• Aerobic gram-positive cocci and Anaerobes

  •Example: Group A strep

  •Compared to animals (cats/dogs):

  Pastuerella multocida is a rare isolate

EMPIRIC ANTIBIOTICS

• Did it break skin?

  •No = no need to prophylaxis

  •Yes = prophylaxis, especially wounds of hands

• My advice: Be careful not to injure yourself when punching someone in the mouth

Multiple Select

Which Abx would you give for human bite prophylaxis?

• Augmentin

• Keflex

• Ciprofloxacin plus Flagyl/Clindamycin

• Bactrim plus Flagyl/Clindamycin

• Erythromycin

Need to cover for Eikenella

• Antibiotics that cover Eikenella and anaerobes

  •Augmentin

  •Fluoroquinalone or trimethoprim/sulfa plus metronidazole/clindamycin

• Antibiotics that do not cover…

  •Cephalexin, erythromycin, dicloxacillin

Wound Care for all bites

• Do not suture cat bites and human bites

• Do not suture crush injuries, puncture wounds, bites involving hands and feet

• Wounds more than 12 hours (24 hours on face)

• Bite wounds in immunocompromised hosts

• Do not use “Glue” to close lacerations.

• Excessive irrigation for all wounds

Fleas, Bedbugs, Scabies, Cockroaches and chiggers!!!

EWWWWWW

Flea bites

Bites typically found:

•Around the waist, ankles, armpits, and in bend of the elbows and knees 

Fleas often jump from rugs, pets, or grass onto lower legs and ankles

• Tend to cause more localized reactions

  Often occur in clusters or groups

• Persistent (>48 hours) papular urticaria (<1cm), which may have a vesicle on top.

  Very Pruritic

  When scratched, may see erosions or crusts

• Fact: responsible for spreading Bubonic plague throughout Europe in the Middle Ages by feeding on infected rats.

Treatment For Fleas

• All sources must be treated

  •Pets, animal bedding, entire house 

• Eliminate both adult fleas and immature fleas in the environment.

  •Aggressive vacuuming of carpets, furniture, and pet bedding

  •Washing pet bedding

Chemical Control

• There are many options:

  •Pyrethrins, carbamates, organophosphate, imidacloprid, fipronil, sodium polyborate, methoprene*

  •*Methoprene (Siphotrol) is a new synthetic chemical available in a spray and fogger that claims to protect against fleas for 4 months.

  •Vehicles include sprays, powders, foams, solutions, foggers, and flea collars

• Pet shampoos remove fleas but don’t have any residual effect.

  Must follow with flea rinse or dip with an insecticide

Scabies

•A mite (Sarcoptes scabiei) which produces intense itching.

Rash generally occurs in the webspaces of the hands > wrists > penis > elbows > feet >genitalia > buttocks > axillae.

•Head is usually spared except in infants.

Scabies

• Usually transmitted by skin-to-skin contact, but mites can remain alive for >2 days on clothing or bedding.

• Mites burrow into epidermis shortly after contact and deposit feces in the tunnels.

• Female mites burrow at night and lay eggs during the day.

• Infestation is usually only by about 10 mites. 

• However, Norwegian (crusted) scabies, may exceed one million (generally seen in persons with immunocompromised state).

Treatment of Scabies

• Individuals and close contacts

  •Regardless of whether close contacts have symptoms

  •Close contacts include sexual partners and all members of the household.

• Topical 5% permethrin, apply at bedtime

  •Apply from jawline down to toes, in every nook and cranny.

  •Treat head and neck only in infected infants

  •Must leave on for 8-12 hours and then wash off.

  •Wash all bedding and clothing in hot water (60˚ C).

  •Can repeat the treatment in 1 week

  •Although no controlled study has proven two applications are better than one.

Norwegian (crusted) scabies

Treat with permethrin daily x 7 days, then twice weekly until cured.

•Also take in conjunction with oral ivermectin.  

You wake up with an itchy red rash on your face, neck, and arms.

You check under your mattress and see this.

What are those?

•Cimex lectularius

Can survive 6–12 months without feeding on human hosts (yikes!)

•Reside in bedding, mattresses, furniture, floors, and walls

Bed Bug Bites

Pruritic rash with erythematous macules, papules, or papular urticaria possible with vesicle

•Similar to flea bites

•Bite reactions occur on exposed sites.

•Face, neck, arms, hands

•Characteristic linear array with two to three lesions in a row

“breakfast, lunch, and dinner!”

Treatment of Bedbugs

• Topical steroid cream may be used for symptomatic itching.

• Place all clothing, bed linens, stuffed animals, etc. into tightly sealed plastic bags and bring to laundry area. 

• Wash and dry both at high temperatures.

• If unable to wash, place in dryer on high for at least 10 minutes or steam clean.

Treatment of Bed Bugs (continued)

• Vacuum everything…

  •Carpets, mattresses, furniture, inside and out. 

  •Empty your vacuum cleaner immediately into a plastic bag while in the infested room, seal tightly, and dispose.

• Don’t forget about obscure places like alarm clocks and electrical switches, etc.

• Consider using a nontoxic spray or traps as additional treatment.

You enjoy a midnight snack in bed and then wake to find a few itchy red bumps…

and then you see this!

Cockroaches

• Some varieties bite, some don’t. The German cockroach (most common roach in US homes) is most commonly associated with biting.

• Cockroach bites are fairly rare.

• Treat bites like any other insect.

  Symptomatic treatment of itching with topical steroids

Chiggers = Mite Larvae

• You can find them throughout the world, but they are most common in the south, southeast, and midwest in the US. Chiggers are particularly active between early spring and early autumn (most numerous in early summer). 

• •Intense itching

  •Last several days

  •Persist even after detached

  •Digestive fluid cause skin cells to rupture. Fluids from the skin cells are then consumed as food.

• 
  

Chiggers

• “Home remedies”

  •Fingernail polish

  •Seal the skin from contact with air

  •With calamine, Vaseline, cold cream, and baby oil

Wasp/Bee sting Treatments

• Remove stinger

  •Need to remove stinger as can act as a foreign body

  •Stinger may have venom sac attached that within a few seconds is empty

• Clean the sting site with soap and water.

• Apply ice

• Oral antihistamines for itching

• NSAIDS or acetaminophen for pain relief

• Complications:

  Rare secondary bacterial infections

Treatment-Fire Ant Stings

• Anaphylactic reactions

  •Injectable epinephrine

• Leave pustules intact!

  •Prevent secondary infection

• Local reactions

  •Oral and topical antihistamines

  •Remove mandibles/stingers if on skin

  •Ants grasp the skin firmly with their mandibles and inflict multiple stings per insect

For next time:

• Envenomations (Snakes, Spiders, scorpions)