Wilderness Bites, Stings, Rashes and Allergic Reactions

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Wilderness Bites, Stings, Rashes and Allergic
Reactions
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A 45 year old male presents with lip swelling
after drinking out of a soda can with a bee
crawling on it
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What type of hypersensitivity reaction is this?

• How should this be treated?

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Immunology Type I Reaction

• Hymenoptera

• Multiple Antigens
• 40-50 Deaths/yr US
• Rare deaths from stings alone (gt 50 stings)
• Africanized Bees

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Types of hypersensitivity reactions

• Type I IGE mediated/ anaphylactic ..immediate
  allergic rhinitis

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Anaphylaxis

• IGE mediated
• 90 urticaria or angioedema
• The more rapid the reaction the more severe
• May be delayed ( up to 48 hours)
• More severe reactions in older individuals
• Look for
• Dizziness
• Wheezing
• Vomiting

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Treatment

• Prevent further stings
• Calm the patient and friends
• Rest
• Elevation
• Ice

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Vive la Difference

• Bees sting once but have a muscular stinging sac
• Wasps can sting multiple times

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Treatment

• Antihistamine
• Benadryl po v. IM
• 50 mg or 1 mg/kg
• H2 Blocker if severe
• Cimetidine
• 300 mg po or IM
• Epinephrine
• Epi pen (jr)
• 0.3mg adult0.15 mg child
• 65

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Treatment

• Prednisone
• Reduces late phase reaction
• 1-2 mg/kg
• Glucagon
• Refractory symptoms on a B-blocker
• 1-5 mg IM
• Albuterol inhaler for wheezing
• Fluids/ pressor support

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What would make you want to evacuate the patient?
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When to Evacuate

• Systemic symptoms
• Diffuse Urticaria
• History of severe reactions
• On B-Blocker
• Refractory to Benadryl

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How long should you monitor the patient?

• 6 hours
• 50 severe in 10 minutes
• Most deaths lt 1 hour
• Rare worsening after 5 hours

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How long to treat?

• 3-4 days with anti-histamines and steroids

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How likely is the patient to have the same
reaction if stung again?
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Good Question!

• In adults
• Variable studies 10 to 60 who had
  Anaphylaxis may have no or mild reaction to
  subsequent sting 10- 20 worse reaction
• In Children
• Rare severe reaction lt 10 y.o.
• 10-20 with severe reaction will have similar
  subsequent reaction.

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What should the patient carry with him in case
this happens again?
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What to Carry?

• Benadryl capsules
• Epi-pen

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What would make the patient consider
immunotherapy in the future?

• Occupation
• Desire for wilderness experience
• Severity of Reaction
• 95 effective
• 3- 5 years of therapy
• Hornets, honeybees, fire ants

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2 weeks later the patient returns to the ED
withMalaise, Joint pain, occasional itching.
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Type III Immune Complex Formation

• Serum Sickness
• 7-14 days
• Malaise, arthralgias, proteinuria
• Arthus Reaction
• Site of the sting
• 8-12 hours
• Blister formation
• Resolve in 7-14 days
• Antihistamines, Steroids if severe

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A 26 year old gardener was cleaning brush near
her cottage. She presents with a pruritic rash on
her neck. What is your diagnosis?
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Cutaneous Lepidopterism

• Caused by the larvae of the Brown-tailed moth
• Treatment
• Tape removal of setae
• Topical steroids,
• Benadryl
• Systemic steroids
• May induce asthma

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Lyme Disease Clinical Pearls

• The erythema chronicum migrans (ECM) rash appears
  in 2-12 days after the bitei.e engorgement.
• It is caused by the spread of Borellia
• A rash that occurs within the first day of a tick
  bite is not ECM.
• 70 of infected patients will get ECM
• ECM may mimic cellulitis.
• Multiple ECM sites immunocompromised or
  systemic disease.

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Lyme Disease Prophylaxis

• Doxycycline 200 mg po once
• Decr. Infection rate from 3.5 to 0.4
• Indications
• gt12 years old ( doxy ok gt8y)
• Engorged deer tick ( if flat no doxy)
• Cant talk the patient out of it.
• ( mother, grandmotheretc)
• lt8 yo????

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Lyme Disease Treatment

• ECM, Bells, 1st degree block
• Doxycycline 100 mg b.i.d. 14-21 days
• Amoxicillin 15 mg/kg t.i.d. 14-21 days
• Serious Cardiac or Neuro
• Ceftriaxone 75 mg/kg daily 14-21 days
• Arthritis
• As per ECM but for 28 days

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Lyme Disease Cousins

• Anaplasmosis
• Causes low platelets and leukopenia
• Babesiosis
• Causes anemia and hemolysis

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A 40 year old man presents with an erythematous
macular papular rash on his bilateral lower
extremities. He was swimming today in Little
Sebago Lake and became very itchy within an hour
of getting out of the water.
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Escagots Revenge or Swimmers Itch

• Cercarial Dermatitis
• May be caused by the parasite Trichobilharzia
  regenti
• Complicated life cycle involving both a bird and
  a mollusc
• When exposed to humans, borrows into skin and
  causes irritation
• Most cases do not require medical attention

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A 22 year old sternman presents with a painful,
swollen left hand. He states he has redfish
poisoning. It is wicked bad this time. What is
his medical diagnosis?
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Erysipeloid

• Well circumscribed erythema
• Fishing, shellfish, poultry industry
• Not systemically ill
• Sensitive to penicillins, cephalosporins,
  fluoroquinolones
• Resistant to vancomycin
• Erysipelothrix rhusiopathiae
• Gram positive rod

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A 5 year old is exploring a tide pool and has
sudden pain in his right foot. Mom sees a dark
dot on the sole of the foot. The dot is the spine
of the Green Sea Urchin (Strongylocentrotus
droebachiensis) What should be the treatment?
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Wounds in a Marine Environment

• Local wound care removal foreign bodies
• Vinegar soaks or hot (105F) water for urchin
  spines
• Immunocompetent no prophylaxis for minor wounds
• Immunocompromised, Liver disease, Cipro 2nd
  line Bactrim

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A 28 year old paddle boarder wearing a thin
wetsuit went swimming earlier today in the river.
He presents to the ED tonight with a painful
itchy rash. What is his diagnosis?
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Sea Bathers Eruption

• Larva of Jelly fish or anemone
• Urticaria or papular within an hour of exposure
• Under swim suit or nape of neck
• Wash with salt waterscrape off cysts
• Antipruritic treatment
• Sun screen may be preventative

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It is early september and a 65 yo man with no
psych history presents with agitation and
confusion for the past 2 days. He has a low
grade temp and complains of nausea and a
headache. What is your differential?
CSF 20 WBC, 90 lymphs Glucose 70
mg Protein 60 mg Gram stain negative
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West Nile Virus

• Flavivirus
• Japanese Encephalitis
• 80 asymptomatic
• 19 febrile illness
• 1 neuroinvasive
• Intermediary hosts Crows/robins

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Eastern Equine Encephalitis

• 1 human case in Maine

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Prevention

• Barrier
• Head nets
• Light colored clothing
• Socks over pant legs
• Behavior
• No scents
• no baths
• Avoid vigorous activity
• Avoid dusk and dawn

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Insect Repellents

• The Pretenders
• Thiamine
• Skin So Soft, bug guard
• Citronella
• Oil of Eucalyptus
• Soy Bean oil ( Blocker)

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Insect Repellents

• DEET is the word
• Safe even for kids
• Long lasting ( Ultrathon )
• Effective against a variety of insects
• 30 enough
• Dissolves plastics
• Seizures

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Insecticides

• Permethrin
• Very effective combined with DEET
• Allethrin
• Thermacell

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Attractants

• The mosquito magnet
• converts propane into carbon dioxide (propane
  tank not included), heat, and moisture to
  simulate human breath